# Plausible Original Concept For High-Fidelity Apocalypse?

Some of you have commented here: "How Do I Supplement Oxygen Intake?." I mentioned confidentiality, but that is no longer going to be a concern. We just want to do this right.

The original concept for the show was 'Bombs dropped for some reason' and the story was a mess, so I was brought on to fix it. Only a small piece of that proposal is introduced in the above-mentioned thread, but that small piece was broken enough for me to take the entire idea off the shelf.

So I turn to you guys. I want something possible (almost LIKELY) enough to be scary. And I don't want something cliche. It is a tall order, I know. Feel free to science the crap out of this, since no amount of detail is unacceptable. Only chains of coincidence and implausibility are ruled out.

WHAT IS ALREADY WRITTEN IN: Mankind is mostly exterminated, big cities become uninhabitable, and food/clean water is hard to come by so that violent theft of food and even cannibalism occur. Funded by a French-German tech-and-pharms company, important world figures are evacuated to an underground shelter in Moab, UT to ride out the disaster. Meanwhile, the people above ground are either killed or contaminated (by some means). The healthy survivors to prioritize the 'fidelity' of the bloodline, as if breeding with the 'contaminated' can lead to the final extinction of the human race (Something incurable and potentially fatal, and likely to be passed down as a dominant genetic trait?). The layman needs to be able to survive the climate outside, but it should be haaaaard.

POSSIBILITIES: Biological warfare, manual climate adjustments, humans vs Earth, etc... are all on the table. Straight-up 'bombs drop' is overdone and Zombies are unacceptable. I would also try to rule out aliens, GMO conspiracies, and specific political leaders.

• If you want to have a look on real threats that could begin an apocalypse, I would advise you to take a look on the Doomsday Clock: thebulletin.org/doomsday-dashboard – Binson Dec 13 '16 at 0:53
• To me, hi fidelity means good sound quality on a record. What does it mean in your title? – kingledion Dec 13 '16 at 0:58
• It's worth noting that bombs drop may be more realistic than some scenarios provided; and that GMO conspiracies with a twist can become a nasty kind of warfare within the plausible range – Zxyrra Dec 13 '16 at 1:51
• I look forward to the day when TV/movie scriptwriters hit StackExchange as a matter of course to the same extent as software developers. +1 for leading the charge. – JDługosz Dec 13 '16 at 6:07
• @o.m. I am not a lawyer ... but so far as I know you can't copyright ideas. The exact answers here would be copyright and under creative commons but the ideas they describe could be taken and built upon. Industry rules/fairness may suggest that a credit for the idea be given to the person who posted it, I've no idea if that is right or not though. – Tim B Dec 13 '16 at 13:59

## Let's make a list, then narrow it down.

Here's the criteria to judge scenarios

1. Kill off most people
2. Make big cities uninhabitable
3. Make food and clean water hard to come by
4. Be predictable enough to evacuate world leaders
5. Be plausible enough that it could occur in real life

Here are scenarios that won't work, but you could handwave anyway. Comment if you think some are worth elaborating on anyways:

• Natural pathogen: Extremely difficult to achieve #1 in the modern day
• Famine: Extremely difficult to achieve #1, #3 globally
• Planetary collision: Violates #1, #3, #4 by doing too much
• Infertility: Violates #2, #3, #4; violates #5 because it is treatable
• Gamma ray burst: Violates #1, #3, #4 by doing too much
• Vacuum decay: Violates #1, #3, #4 by doing too much
• Grey goo: Violates #1, #3, #4 by doing too much; violates #5 somewhat
• AI apocalypse: Violates #1, #5

Now let's talk about some approaches that might work.

## 1. Nuclear War

This is a promising one, and many organizations take it seriously. The idea behind this is that warfare using nuclear weapons would contaminate the environment, from weeks in some areas up to decades in others - and trigger catastrophic events that would cause more problems.

Consider that this could deplete the ozone, causing a "nuclear summer" and hot conditions, or release clouds of ash and particles, causing a "nuclear winter" when less light reaches Earth. Either is plausible.

1. High mortality rate is inherent with radiation; if you hit the cities, it also kills a significant number of people
2. Boom. We've taken care of the city inaccessibility part
3. Contamination will be rampant! Food and water will have to be filtered / grown far, far away or sheltered from blasts (and in specific areas dependent on winter / summer scenario)
4. If tensions escalate, yes, you can evacuate people.
5. This is plausible! As previously stated, this is taken seriously.

## 2. Biological warfare

.. is the use of a (possibly engineered) pathogen, chosen for specific qualities, distributed in specific places, with the intent of causing as much harm as possible. If an organization with genetic engineering capabilities and enough money has bad intent, they can pretty much do this in real life already.

Consider a conventional bacteria or virus "plague" that spreads rapidly across the population, and lies dormant in corpses, making populous areas less safe. Eventually, cities may become safer, but for a while they will be contaminated.

Alternatively consider releasing a virus or set of viruses in major cities, parks, events etc. that causes rapid cancer in its victims. Gruesome, deadly, spreadable, and unique.

1. If your organization plans it right, they can kill off most people
2. Addressed inaccessibility above: cities have more corpses and more contaminated supplies
3. See the above - any food or water that had contact with humans will either have been looted or contaminated
4. This is reasonably predictable - if it is clear there is an intelligent person, group etc. causing the change, world leaders will feel threatened.
5. This is plausible! Fully within the realm of modern science.

## 3. Climate change

... has been associated with rising seas (eliminates coastal cities), air pollution (remaining cities), the pollution of water, and making it harder to grow crops. Perhaps your show takes place in a world where we failed to save the planet, then most of us died, becoming scavengers in the ~desert~.

1. May increase risks of cancer, diseases etc. as populations grow closer; could eventually lead to less people as there is less hospitable land
2. Big cities will be the most polluted. Even after some years, they may not be safe to breathe in (or even comfortable)
3. Less accessible farmland and more pollution will make food and water precious commodities
4. Also predictable - not necessarily an instant "relocation"-type event but it could be workable
5. This is plausible because it is based off of scientifically supported predictions

## 4. Asteroids

Perhaps astronomers discover that no, that asteroid we said will always just swing by is actually going to collide with us, and there's no way to stop it. Of course, it can be small enough to avoid a dinosaur-level extinction while still releasing a ton of heat, radiation, and particles, making life on the surface difficult, and prompting foreign leaders to move somewhere safer.

1. Climate-related effects may kill a significant portion of the population
2. Cities will be descend into anarchy close to the impact date; this could cause some serious problems that lead survivors to avoid them (bombings, etc)
3. Less farmland, more contamination could result in less food and water available
4. The basis of this event is a prediction; there should be time to evacuate your world leaders
5. While the sudden discovery of an asteroid headed toward Earth is .. unlikely - it's not impossible.

## 5. Coronal Mass Ejections

The basis of the Maze Runner Series' apocalypse (spoiler), ejections from the sun are unpredictable and very hard to stop. They may result in a potentially hotter world, with damaged satellites and electrical systems. If you make your event sufficiently strong (unlikely but definitely possible), it could cause environmental damage and civilian deaths.

1. If the event is powerful, sure.
2. If the last major ejection to hit Earth severely interfered with telegraph wires (1859) imagine the damage to modern technology that would occur
3. The loss of infrastructure, crops etc. may cause a descent into anarchy, making food and water precious commodities
4. This is not predictable enough to move your world leaders prior to the event, but you could consider doing so before things descend into anarchy.
5. This is plausible and a genuine concern.
• Natural Pathogen is super easy to have happen in the modern day. Our antibiotics are making us selectively breed super-illnesses, and our transportation networks allow these illnesses to spread faster than ever. Find a bacteria which is good at killing humans (and becoming transmitted) and has resistance to common antibacterial agents and you got a modern-day plague. Also, consider that multiple problems can happen at once! Not as easy to tell in a story, but certainly more realistic. – PipperChip Dec 13 '16 at 2:42
• @PipperChip: The problem with natural pathogens is that a pathogen that kills off its host is an evolutionary failure, so it fairly quickly evolves not to kill off most people. Really the only way to get high mortality from a natural pathgen is through a virgin field epidemic: introducing something that is common in one population into another with little natural immunity, the classic case being the diseases the Europeans unwittingly introduced to the Americas. – jamesqf Dec 13 '16 at 3:30
• A additional bonus for asteroids are if you have a limestone impact (say like a shallow sea impact)you have widespread acid rain that will kill a lot of crops, even a normal ocean impact will cause days of rain and thus widespread flooding. Flooding coincidentally also contaminates water sources which can trigger disease outbreaks. – John Dec 13 '16 at 4:06
• @Zxyrra Good point. Natural pathogens tend to be worse when those kinds of systems are already in disarray (eg. Spanish Flu). In real disaster scenarios, they always come after, and so should feature in any "high fidelity" fiction. The anti-climax death-by-blood-infection in Cormac McCarthy's The Road comes to mind. But your list is about primary triggers. Agreed, a superbug is not likely to suddenly jump all those controls by itself. – Ryan Mills Dec 13 '16 at 4:17
• @jamesqf A pathogen doesn't need to preserve it's host. All it needs is to preserve it's host long enough to infect other host. – Agent_L Dec 13 '16 at 12:57

A lot of the good ideas for these apocalypse scenarios have already been done, although unfortunately they are often done badly (most asteroid impact scenarios for example have horrific scientific flaws).

There is one idea I can suggest though that should achieve most of what you need and that I don't think I've seen done before.

A small rogue planet (lets say around the size of mercury) enters the solar system, astronomers detect it. There is much rejoicing at the chance for research it presents. Then as more observations are completed there is concern, then fear. The orbit will take it very close to earth.

There is panic and mass hysteria, people are building survival shelters and mobs run wild with looting. The orbit gets calculated, it's definitely on a collision course. But then....it hits the moon, not earth. We're saved!

But not entirely, the impact shatters the moon, sending chunks flying in all directions and turning the remainder into a molten ball of glowing rock.

Of the combined Moon+Exomercury mass:

• 25% is boosted out of earth orbit by the impact.
• 50% remains as a new molten and glowing satellite in an elliptical orbit.
• 25% is thrown away from the new moon as shattered fragments but does not have enough energy to escape Earth's gravity well. It enters into orbit around earth as a new planetary ring.

A newly formed ring with no shepherd moons and subject to disruption from the glowing molten inferno that used to be Luna is going to be unstable. The rain of rocks will begin shortly after the initial impact and continue for centuries or even millennia afterwards.

In addition the shifted orbit of the moon and new elliptical orbit will mean huge and unstable tides, further disrupting life on earth. In the resulting chaos of tidal waves and rocks from the sky numerous nuclear power stations melt down, get hit and thrown into the air, etc.

This would also trigger volcanic activity and earthquakes as the new stresses on the Earth's crust shifted things inside our planet. At the same time ash fills the air causing the temperature to plummet and now crops fail and winter comes in hard on top of everything else.

The result is a shattered environment where it is possible but extremely dangerous to survive on the surface. Radiation, toxic heavy metals and disease means that both the survivors and their DNA are damaged. They would have trouble carrying babies to term and there would be a high risk of deformity so people from a secure underground shelter would have a good reason to be wary of them.

The initial premise (rogue planet) is pretty unlikely but only the one unlikely event is needed, everything after that just follows fairly logically. This also gives you an ongoing surface threat (a reason to stay underground) and some really spectacular visuals. Imagine a glowing red molten moon twice the size of our normal one (at closer approach, the size would vary during the stages of its new elliptical orbit), with a ring extending across the sky. The sky itself would (especially in the early days, this would reduce over time) constantly be aflame with smaller meteors burning up while occasional larger ones would make it lower or even impact the ground.

• Nice answer! It avoids the typical tropes without being absurd. Good backdrop for a show. – JBiggs Dec 13 '16 at 18:54
• There's a book that's exactly this: Neal Stephenson - Seveneves. Apparently so much mass entering the earth's atmosphere would produce enough heat to boil the oceans. – Ryan Mills Dec 14 '16 at 0:48
• 3 asteroids are half the size of the moon. One of them has been getting knocked around by other smaller asteroids for centuries or millennia and finally one knocks it into an unstable orbit towards the sun. – Tracy Cramer Dec 14 '16 at 1:13
• A company has decided to mine an asteroid. They are bringing it back to Earth when something goes wrong and the thrusters turn on too much or too little and instead of entering orbit, collides with earth. – Tracy Cramer Dec 14 '16 at 1:16
• @RyanMills - Exactly what I was thinking. No rogue planet there, but just the mass from the moon is enough to cause devastation. – Bobson Dec 14 '16 at 2:23

The problem with storytelling is that some things that are scientifically plausible are simply unbelievable to an audience. This forum discussed that problem with discussing how to survive falling from an airplane. Well, I've got one that's plausible but might not work for believable.

Consider the Antarctic ice sheet collapse. Here: http://www.sciencemag.org/news/2015/11/just-nudge-could-collapse-west-antarctic-ice-sheet-raise-sea-levels-3-meters The typical models show a collapse happening over centuries. I'm not suggesting you mess with that. BUT. There's an interesting scenario that shows up in some ice models: ice can melt from the bottom up. As you see in the article, the large pools of warm water can form on the inside. It is plausible for a single pool to cut through under Antarctic ice across the continent and form a river, which the works its way sideways.

Now check out this National Geographic report of the Larson shelf collapse in 1995: http://news.nationalgeographic.com/2016/04/160412-ice-sheet-collapse-antarctica-sea-level-rise/

The rate of ice melt is pretty fixed. Put X energy in, Y ice turns to water. But if we carve out the underside of the ice first instead of melting down, you get a moment when the ice cannot hold its own weight and it collapses -- again, see the article. But what happens if the part that collapses is over water? It falls in, like dropping an ice cube in a bowl. And that causes waves. Think about the tsunamis from earthquakes: those in Indonesia a few years ago came from shifts of a couple inches. If the West Antarctic ice sheet were to just drop in to the water, it would displace 10 FEET of water and a quite epic tsunami.

It's low probability. But it does show up in models from time to time. It's my favorite doom scenario.

• To make that more TV friendly, have an asteroid or meteor strike the dead center of that mass (after it's been weakened by the undercutting of warm water), which puts a mass of head and kinetic energy in the "strongest" part of the sheet. Makes for great television, and while it's not really the direct cause (the undercutting is) it seems actiony. – Marshall Tigerus Dec 13 '16 at 18:13
• I wouldn't say the probability is that low. The problem, for story purposes, is that it doesn't kill off enough people, and leaves large areas unaffected. For the US, Miami, Houston, most of the east coast seaboard would be gone, but folks in Denver wouldn't notice until they turned on the TV. – jamesqf Dec 13 '16 at 18:15
• @jamesqf true, but the trade links that support a lot of places would be gone, a huge swath of arable land is unusable for a generation, and the ensuing chaos seems about the right threat level for this question's goals. Not noticing instantly is important: you need time to react to get people to shelters and safe havens. – SRM Dec 13 '16 at 19:05
• @marshall_tigerus as a viewer, it would really strain my credulity that the rock just happened to hit THAT point in the ice. Personally, I wouldn't make it passed episode 1 of a show that started there unless some alien intervention was quickly theorized. There's low probability and then there's "somebody lined up to take that shot." – SRM Dec 13 '16 at 19:12
• @MarshallTigerus That sounds awesome. One single crazy coincidence like that is completely believable. It's when there's a whole string of stuff that just happens to be the way it needs to be that we have a problem. – DCShannon Dec 14 '16 at 0:46

# Stop! Take a breath. Do not tell us the world. Tell us the story.

Whoa, hold it right there. Your premise is still a mess...

• An apocalyptic event has happened and killed a majority of the world's population. Ok, I can get that.

• The surface is as good as uninhabitable unless you feel like contracting a serious case of The Malady™. Very well, I can get that too.

• Some of mankind has moved underground. All right, that sounds like a good thing to do if the surface is uninhabitable.

• This one company has gotten all the important people together in this one place... wait, what?!

This is where it all becomes totally absurd. What happened to all the governments in the world? What happened to all the super-national organisations like the UN? What happened to all the other companies and multinational conglomerates? Why is this one company suddenly such a big focal point. And how can it even bother to remain a company when the entire world has gone to the crapper?!

I would say that you are asking us the wrong question. You are asking "Here is a world. How can I fix it?".

What you should be asking: "Here I have a story. It needs a credible world/setting. Where can I start?".

So... stop, do not try to fix the world because I can tell you already now that the world is most likely un-fixable, at least if we are staying with the premises that you stated.

Instead: tell us the story. What is the story that you need a world for?

What you have presented is (somewhat of) a High Concept. But a High Concept can never make for a TV series/film/novel/whatever on its own. It needs a story.

A prime example of this would be the film Ultra Violet. It is an amazing setting/world. Look at the background material and you will find that the world that Kurt Wimmer has created is very well crafted. It is interesting, it is consistent and actually quite cool. But the film fell flat on its face; it was a bomb. I dare say that the main issue with it was not bad CGI or anything of the sort that is usually mentioned, because you can overlook things like that if the narrative is good enough. But the narrative was not good. The entire film was a world in search of a story, without finding one. And for that it failed so badly it became infamous.

Hence: tell us the story, and we can help you build the world. We also have some hints about the air and mood, and some story elements you need. From this we can help you build a credible High Concept that does not fall apart at the first closer look.

• Yeah, I think they bought some sets and costumes for cheap and need to make a show out of it. – Samuel Dec 13 '16 at 20:35
• Good points :) Though OP did not exactly specify that everyone important got to Moab, UT, I took your premise into my answer. Though I admit the explanation for most important folks being there still could be optimized... – Zommuter Dec 16 '16 at 15:25

## Prion Disease

Viruses and Bacteria too mainstream for you?

Read up on the terrifying world of misfolded proteins!
https://en.wikipedia.org/wiki/Prion

Some features are

Add in a new transmission vector like rats or mosquitoes and you have a terrible pandemic on your hands.

• Prions are terrifying – Marshall Tigerus Dec 13 '16 at 18:34
• Also, prions can't be "killed" by standard sterizilation techniques such as alcohol or autoclaving. At a place I used to work, the lab next door regularly needed to dispose of prion waste. Their solution? Autoclave it twice. – Ryan Mills Dec 14 '16 at 0:36

# Gene Drive

A recent trend in genomics, relevant mainly to pest control, is gene drive, or "super-Mendelian" inheritance, nowadays done via the insertion of active elements into germline DNA.

For a slightly dramatic take on it, see here.

The main techniques use CRISPR-Cas9, a genome editing technique that has become widespread over the past few years.

Apparently, the original authors who first applied CRISPR-Cas9 to inheritance (gene drive) were surprised that it was so effective. Basically, by using gene drive, via insertion of active elements such as CRISPR-Cas9, one can over-ride the usual laws of inheritance and force all offspring to have some desired trait.

A problem with CRISPR-Cas9 and similar is that, while they are extremely active (or efficient: you don't need much of it to edit a lot of DNA), it's hard to check for what else they are doing to that DNA. Unlike traditional tools used to make GMOs, which are the result of generations of research and contain various "flags" to show off-target insertions etc, CRISPR-Cas9 and similar can change DNA and leave no other trace. This makes it hard to show that whatever you have done has been specific, ie. acted only on the desired target site in the DNA. Eventually, full genome sequences will be used as quality control, but we are not there yet.

So, right now, we've very rapidly adopting a highly efficient DNA-editing system with little quality control, and applying that to directing inheritance.

Let loose on the plant or animal kingdoms, a few of these could plausibly produce the stated scenario.

# Target species

How bad this becomes depends on the life-cycle of the species that happen to be targeted. Reported examples can affect up to 99 % of progeny, and take as little as two generations to become completely entrenched. As it works via inheritance, long lived species such as humans and many plants would not be directly affected, until they need to reproduce. However, most food crops have been selected throughout human history for very short (sub-annual) life-cycles, making them especially vulnerable. Fish harvested by humans are long-lived but have short reproductive cycles. Introduction of errant gene drive constructs into any of these would quickly fill their genomes with any number of blights.

The list of target species could be broadened indefinitely were a CRISPR-Cas9 construct made to "species-hop". They obviously don't do that right now, as gene drive requires sexual reproduction to spread. Thus, the most plausible, immediate scenario would be a low number of species that have been targeted deliberately* by CRISPR-based constructs.

CRISPR-Cas9-based DNA-editing technology is very easy to acquire and use (it was partly designed that way). It works in any species, and has been shown to be extremely successful across the board.

*User-friendly, searchable table of comercially-available CRISPR/Cas constructs. https://www.addgene.org/crispr/validated-grnas/

• So… zombie mosquitoes? – JDługosz Dec 13 '16 at 6:03
• And undead yeast! You heard it here first. – Ryan Mills Dec 13 '16 at 8:43
• Good answer but it’s I think exaggerating the dangers introduced by CRISPR/Cas9 off-target effects. In particular, their detection isn’t all that difficult. After all, we can just sequence the host genome after insertion. This isn’t done currently simply because it’s unnecessary and expensive. And, just to avoid the impression that there’s a limited catalog of CRISPR targets: guide RNAs can be designed fairly easily for (almost) arbitrary targets, using online tools. – Konrad Rudolph Dec 13 '16 at 13:28
• If you add in a carefully engineered virus that would insert a genetic alteration like this into humans which is easy to transmit and highly survivable, you have something that might fulfill all the apocalyptic criteria. – JBiggs Dec 13 '16 at 19:02
• @Konrad Rudolph Sequencing the host genome is much more difficult / expensive than doing PCR off a cassette, which is how we used to rule out extra integration sites, and hence it's never done. Actually I was looking for a list of species that have been successfully modified to date by CRISPR-Cas or similar. Do you know of any?. Not finding anything, I just put in Addgene's products. Thanks for your link to the design-an-oligo tool. – Ryan Mills Dec 14 '16 at 1:11

While the concept of a Franco-German conglomerate choosing to house their pick of important people in Utah is intriguing enough, I think the key issue to be solved is how to make an apocalypse fast enough to "work" without being instantaneous (we have to get these people to Utah somehow....)

The issue with most cosmic level catastrophes like a Gamma ray burst is they appear at the speed of light, so there is no warning before the onset of the catastrophe. Solar coronal ejections creating a Carrington Event give you about 8 minutes warning, hardly enough to speed dial all your contacts on the emergency bug out list, much less transport them to Utah. An incoming asteroid or comet gives us either a "surprise!" moment, like the Chelyabinsk meteor, or you calculate the orbit years in advance, much as in the movie "Deep Impact"

Many of the other possible apocalyptic scenarios listed by Zxyrra and the other posters have similar issues in timing, either everyone see it coming in advance (and can take steps) or it springs up unexpectedly, with zero prep time.

Funded by a French-German tech-and-pharms company, important world figures are evacuated to an underground shelter in Moab, UT to ride out the disaster.

So we have the culprits, and their way of escaping retribution until their evil plan unfolds and they can come out and create the "New Order" in the shape they desire.

Since this is a pharma company, they should have some experience in genetic engineering, but since attacking people is bound to get a prompt (and once the world's governments discover the source of the pathogen) pretty violent response, the pathogen is designed not to attack people at all, but rather something critical to the global infrastructure, like refined hydrocarbons. The world will come to a pretty crashing halt, but before this happens, all the important people were at a convention in the Untied States, and then went on vacation....

To make it even more scary, the pathogen will most likely mutate once all the easily accessible hydrocarbon fuels are turned into varnish, so they might evolve to start eating plastics and other polymers. Down in the hole, the plotters are starting to realize their careful schemes may be for naught (and aren't the seals between the shelter and the outside world made with plastic gaskets....?)

This isn't what we talked about, Andre...

You can now run two parallel plot lines as the survivalists in the outer world contend with a Mad Max like planet (but no souped up V8 interceptors) while the people in the shelter discover things are not looking quite so rosy for them either....

Not unless he's going to push this by hand

Apocalypse by Singularity

Our world works the way it does because goods have value, people are finite individuals, and no one is so very much smarter than the rest that they can remain on top for very long – among more concrete givens like, say, the arrow of time.

The Singularity changes one of those things, rendering events prior to it inexplicable to those who survive it, and the events within it obscure to all observers.

Imagine that tomorrow, someone uses genetic modifications to make themselves immortal or super-intelligent? That tomorrow, a company looking for rapid scaling creates a factory that can literally copy itself from available raw materials? That a scalable computer system ends up outperforming humans at all cognitive tasks, or that incredibly clean, cheap, and plentiful energy is discovered? Great achievements come with great risks – and so do great tragedies. In 1492 the New World experienced something like this when Europeans, gifted with certain technologies and circumstances that made them indescribably powerful in comparison to the aboriginal inhabitants of the Americas, discovered these continents. Catastrophic change came to the Western Hemisphere on a timescale difficult to comprehend in its brevity.

My favorite specific type of Singularity is probably an Economic Singularity, because I tend to think it’s a little more probable and a little easier to grok than some of the other ones. It goes something like this:

Tomorrow, someone releases an open-source design for a robot that can gather all the raw materials for its own construction on its own, and then use these materials to build copies of itself – or whatever else you program it to build. In fact, with a little work, you can get it to work together with its copies to build even very large things that you ask it to build. If you have the blueprint and your robot, you basically own it, apart from acquiring the raw materials. Modern economic systems, based on traditional kinds of wealth inequalities, break down utterly. There is no physical market anymore; only the digital market. The change is very fast – too fast for nations or companies to adjust. Within a year this robot is available to basically everyone on Earth. Piracy, never really stomped out before, makes it impossible to harness this new completely digital economy, and so it becomes very difficult to have wealth of any kind. This makes it kind of hard for nations to fund things like militaries, which they’re going to need to combat the robot armies and nuclear bombs that some persons of more dubious moral stature will no doubt begin building immediately.

At some point in this tumbling avalanche of economic turbulence, and in no particular order:

• bombs start to go off, and fingers start to be pointed – factions rise and fall.
• people trying to do REALLY big things with their robots realize that cities represent awful good accumulations of the kinds of raw materials you need to build those really big things
• lots of people get their robots taken away by people who use their robots better, leading to a new kind of hyper poverty/wealth dichotomy
• the Earth’s climate, already not doing so great, is caught in the tug of war between all this rampant activity and the few people trying to use their robots to build things that will alleviate climate change. In any event, large portions of the surface of the Earth are stripped bare and vast underground honeycombs of mining activity become warrens for the dispossessed seeking shelter from the increasingly hostile surface.
• at some point, due to the inherent error rate in all copying, a robot makes a copy of itself that is flawless in all design specs except the one where it necessarily does what its master tells it to do – and it just starts making, non-stop, copies of itself. Enterprising souls attempt to curb the oncoming grey goo-ish scenario by making copies that convert specifically that mutant strain of robot to raw materials for making themselves and unleash them into the robosphere, and perhaps at some point another viable mutation or twenty occurs to these two lineages, splitting the uncontrolled robots of the world into multiple competing, interconnected species which are slowly outcompeting the natural flora and fauna of the planet. At some point, one of these mutations develops a taste for another bountiful resource on the surface of the Earth – human flesh. It’s nothing personal, but we’re a great pile of useful carbons just waiting to be combusted as fuel, or maybe turned into lubricant. Some, desperate to survive in areas where no defenses against these new superpredators exist, go to the extreme length of designing robot bodies for human brains to live in, to appear like their own predator in order to survive. Unable to reproduce as humans once did, their continued existence now depends on their ability to carry on gene splicing using blueprints available in their robot host’s memory banks. Breeding with baseline humans is not only undesirable to both parties, it’s extremely difficult.

In short, read Philip K. Dick’s Autofac, but take more drugs than Dick did.

P.S. Although William Gibson has told me he doesn't think Technological Singularity is a Thing, I believe he has subconsciously been working on extrapolations of leadups to Economic Singularity in his more recent work, beginning with All Tomorrow's Parties and finding an especially subtle outlet in the finale to his Zero History.

• That actually sounds too catastrophic for the asker's requirements. – DCShannon Dec 14 '16 at 0:56
• @DCShannon nah, not really. It's a far cry from real gray goo, and the saving grace of the whole thing is that when eventually the robots start eating each other, we get a little breathing room at last. You know, after it's completely trashed our entire civilization, planet, and possibly solar system. – Adam Wykes Dec 14 '16 at 1:28

## Supervolcano eruption

About 75,000 years ago, a tremendous volcanic eruption occurred at the present site of Lake Toba in Indonesia. It ejected tremendous amounts of ash and sulfuric acid into the stratosphere. It is hypothesized that this caused a global volcanic winter that lasted 6–10 years, and that this drastic change in climate nearly wiped out the human race. These conclusions aren't universally accepted, but they're plausible enough that you could handwave them for a TV show.

Your show occurs a generation or two after a similar supervolcano eruption; the global volcano winter is predicted to last for 50–100 years. After the volcano, catastrophic crop failures occurred for several years running. In the first few years after the eruption, the company (for whatever reason) built this underground sanctuary, powered by a nuclear reactor. On the surface, mass starvation occurred; a few farmers were able to scrape by in the countryside by growing some particularly hardy crops, but the major cities were reliant on food being shipped in from outside, and now nobody lives there. (The survivors might venture into the cities to scavenge for supplies from before the catastrophe.)

The people in the below-ground colony are told that there is a plague that has infected all those left behind on the surface. However, there is no real plague. Shortly after the colony was founded, there was a large amount of unrest inside because of the large number of people left outside (particularly the friends & families of those locked out.) The company fabricated the notion of a plague in order to have an excuse for not bringing more people in: "We can't let them in, they might be infected."

If you really want to make the company sinister: instead of fabricating rumors of a plague on the surface, they actually genetically engineer a disease and release it onto the surface.

As far as where the this supervolcano eruption occurred: how attached are you to Moab? One of the more likely candidates for a supervolcano eruption within the next few million years is the Yellowstone caldera, and Moab is probably too close to that to be chosen as a site for an emergency refuge. A bunker in China or Australia might be able to survive, though. Alternately, there have been large eruptions of this scale with the last few million years in New Zealand, Indonesia, and Argentina.

• Note that it is theoretically possible to jump-start a supervolcano with hitting the opposite side of planet with asteroid ;) (see en.wikipedia.org/wiki/… ) Also, i think a supervolcano is end of the game for humanity not "we can live thru this apocalypse" OP is asking for (see en.wikipedia.org/wiki/Siberian_Traps etc...) – Jan 'splite' K. Dec 14 '16 at 14:21
• (heh, just found out that the Wilkes Land crater is almost antipodal to Siberian Traps -- maybe i doesnt even have to go to Mercury for example of jump-starting supervolcano :) ) – Jan 'splite' K. Dec 14 '16 at 14:29
• @Jan'splite'K.: A mass-extinction-level supervolcano eruption like the Siberian Traps would definitely be too large. However, as noted above, humanity did (barely) survive the Toba supervolcano eruption 75,000 years ago. There's enough wiggle room in there to make things dire but survivable. – Michael Seifert Dec 14 '16 at 14:48

Why on earth do they move underground? It is not at all easy to find a reason for an underground shelter.

Since the "important world figures" are to be protected in an underground shelter it means that there is something in the air which is very dangerous. (There is no reason to burrow underground for a simple famine, or glacial maximum or other disaster which does not make air dangerous.) The danger can come either from radiation from those undesirable bombs, or from some sort of pathogen, or from a toxin. (Cannot be plain UV because they wouldn't need to borrow underground, they would simply stay indoors.) I would say that toxins are out simply because I cannot see how to make such a huge amount of toxins as to render all the atmosphere poisonous (and then recoverable in a reasonable amount of time). That leaves radiation or pathogens.

And even if air is dangerous, why underground? We are perfectly capable of making air-tight buildings.

Since the upground people are to be undesirable mating partners it follows that the pathogens must somehow affect the germline. This means some sort of retrovirus. Retroviruses are normally not very virulent, maybe some explanation must be given how a retrovirus can kill so many people so quickly. The trouble with viruses is that once most of manking has died the viruses will also die (or chnage into a survival form, which is much more manageable); the wealthy survivors simply need to clear a sufficiently large area and they can move upground; this may need to be addressed.

An alternative would be to imagine a swarm of rocks coming from space, maybe the remnants of an asteroid. They could in principle be detected early enough to allow for building the shelter, and there is nothing we can do to protect against them. But in this case, what transforms upground people into hideous mutants? Not to mention that if Earth is to be subjected to a prolonged meteorite bombardment there may be severe environmental effects.

And why on earth is the shelter dedicated to "important world figures"? Once the disaster strikes, important world figures are no longer important. It is understandable to give some of the places in the shelter to important people in American politics (who must approve the plan), and maybe to handful of financiers (who must provide the funds for the plan), but the rest? Wouldn't it be more logical to shelter people who actually have something to contribute to the reconstruction effort: engineers, chemists, mechanics, soldiers, doctors, and, of course, as many women as possible? Remember that by far the main factor in re-establishing the population is the number of women. (So the shelter should probably have female engineers, female chemists, female mechanics, female soldiers and female doctors, with a small number of men to provide a certain degree of genetic diversity.)

• There is no reason to burrow underground [unless there's something in the air] I have to disagree completely. Perhaps there's anarchy, or disease, or it's too hot, or it's too cold - there are a plethora of things besides the air that can drive people into hiding. – Zxyrra Dec 13 '16 at 1:38
• The OP describes a world in anarchy. I doubt that staying in a building aboveground is safer than moving below ground regardless of the cause of this apocalypse. – Zxyrra Dec 13 '16 at 1:39
• Finally do you think the engineers, soldiers, mechanics, chemists have the money to build these shelters? The rich can afford to, which is why they do, in the OP's scenario. Sorry I'm pummeling this answer with comments but I strongly disagree. – Zxyrra Dec 13 '16 at 1:40
• But almost all people are dead... So there is no army to besiege the castle. And a building upground is very much easier to keep at a right temperature than a mine. And the state has much more money than any billionaire. – AlexP Dec 13 '16 at 1:41
• Clearly there are some people, and if these some people find guarded buildings aboveground (or even places they cannot access) they will assume they have not been raided - and they will try to get in, for shelter or for food. – Zxyrra Dec 13 '16 at 1:42

https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis

Seas warm; methane deposits are suddenly freed from seabed. Poison gas clouds billow from the oceans; most things die.

In general, take a look at the Permian Extinction. I wish as many people knew about this as zombies; it's a hell of a lot scarier.

## "Normal" Accidents

"Normal Accidents: Living with High-Risk Technologies" is a 1984 book by Yale sociologist Charles Perrow, which provides a detailed analysis of complex systems. Normal accidents, or system accidents, are so-called by Perrow because such accidents are inevitable in extremely complex systems. They are essentially the embodiment of the "For Want of a Nail" proverb. Given the characteristic of the system involved, multiple failures which interact with each other will occur, despite efforts to avoid them. Perrow said that operator error is a very common problem, many failures relate to organizations rather than technology, and big accidents almost always have very small beginnings. Such events appear trivial to begin with before unpredictably cascading through the system to create a large event with severe consequences. Perrow identifies three conditions that make a system likely to be susceptible to Normal Accidents. These are:

• The system is complex

• The system is tightly coupled

• The system has catastrophic potential

Such accidents are unavoidable and cannot be designed around. The inspiration for Perrow's books was the 1979 Three Mile Island accident, where a nuclear accident resulted from an unanticipated interaction of multiple failures in a complex system. The event was an example of a normal accident because it was "unexpected, incomprehensible, uncontrollable and unavoidable":

The accident began with failures in the non-nuclear secondary system, followed by a stuck-open pilot-operated relief valve in the primary system, which allowed large amounts of nuclear reactor coolant to escape. The mechanical failures were compounded by the initial failure of plant operators to recognize the situation as a loss-of-coolant accident due to inadequate training and human factors, such as human-computer interaction design oversights relating to ambiguous control room indicators in the power plant's user interface. In particular, a hidden indicator light led to an operator manually overriding the automatic emergency cooling system of the reactor because the operator mistakenly believed that there was too much coolant water present in the reactor and causing the steam pressure release.

## Snowballing Problems

Essentially, the idea is that one seemingly small problem occurs, that unexpectedly leads to another larger problem, and that problem begins to set off a series of uncontrollable, unanticipated, unresolvable problems of catastrophic proportions.

So, I think you could start with almost any problem and then find ways to create associated problems that culminate in a global catastrophe. My point is that none of the events in the series have to be major things like nuclear war, but could be something like the Deepwater Horizon oil well never getting successfully capped. If it never got capped it could lead to massive ecological damage, which could cause health problems, massive economic problems, and these could all lead to financial collapse of the insurance industry, setting off a global economic crisis the world could not recover from. That could leave the world impoverished and decaying, rather than thriving and well-maintained. This lack of education and proper maintenance could lead to several nuclear accidents of varying degrees of severity. Widespread lack of wealth could lead to college educations becoming unaffordable, which in turn leads to a severe lack of educated, competent workers. Economic collapse and industrial collapse could spiral out of control in first world countries, leading to massive tailspins in less developed nations. After generations of increasing decay, society could be plunged into a scenario almost impossible to recover from. That's basically how civilizations fail--Rome fell because of lead in the pipes.

## Some Problems

Some possible initial problems could be:

• Nuclear accident(s) (Chernobyl irradiated 200,000 sq.km.)

• Deepwater Horizon accident failing to be contained (maybe with the oil eventually catching fire all across the ocean too)

• A cross-continent natural gas pipeline exploding, in multiple places simultaineously

• Riots spreading throughout a nation

• Bioweapon accident, chemical weapon accident or nuclear weapon accident

• A massive scandal revealing overwhelming political corruption

• A global recession like the economic collapse of 2008

• Terrorist attack

• Hostile foreign power systematically undermining and degrading a nation

• Y2K type of collapse

• Global malware infestation, like ILOVEYOU

• Some other kind of civilian "weapon of mass destruction", like derivatives (I don't know if there are other kinds of WoMD than financial instruments)

• Extensive droughts leading to loss of drinking water

• Droughts leading to excessive wildfires

• Ancient pathogens being released from melting permafrost

• Overwhelming number of antibiotic-resistant strains of bacteria

• Earth's magnetic field flipping

• A massive earthquake that destroys California and the much of the rest of the United States' west coast

• Global irradiation: the radiation equivalent of global warming--global warming is the gradual buildup of CO2 to catastrophic proportions, so global irradiation would be gradual buildup of radiation until it becomes a significant danger to all of humanity

• Sudden melting of all icecaps on Earth: say nuclear weapons like Russia's Satan 2 missiles with payloads capable of destroying all of Texas, France or the U.K. simultaneously explode on the North and South poles, Greenland, and other ice shelfs, accelerating global warming so suddenly that all ice on Earth melts within 1 year, thereby raising sea levels by 70m (230ft.) within 1 year. This would cause many nuclear power plants to be submerged, since they take at least several decades to be safely decommissioned. In addition, the pollution from so many cities suddenly being underwater could be catastrophic, to say nothing of the chaos and panic that would sweep over the world as all major coastal cities went underwater.

Any of these could easily lead to a chain reaction of cascading problems, which become overwhelming when they all compound on top of each other.

• @Daerdemandt Thank you. I've fixed all the broken links now. – Thom Blair III Dec 13 '16 at 18:03
• @ThomBlairIII I am sorry but the snowballing nuclear meltdowns is a ludicrous scenario. Chernobyl #4 was not a meltdown. It was a case of a run-away reactor that exploded extremely violently — twice — and then smoldered for over a week. And even with that, the remaining 3 reactors at the plant remained in operation until the year 2000. A meltdown is nothing like that, and will not force an evacuation of the sort that other reactors would be left to melt down in other sites. If there has been a meltdown nearby, one of the safest places to be is actually inside another NPP. – MichaelK Dec 14 '16 at 13:16
• @MichaelKarnerfors Wow! That's awesome!! That eases my mind a lot. – Thom Blair III Dec 14 '16 at 14:34
• Ok, thank you! I really appreciate your help. – Thom Blair III Dec 14 '16 at 15:12

There have been different individuals and groups pledge to take on climate change personally. One plan involved 'whitening' ocean clouds with a metallic powder to increase reflection. The science made some sense, but I believe they talked the guy out of starting it himself without an international consensus.

Garage biohackers already have the ability to release a myriad of crazy self-replicating ideas we've come up with to solve global warming, without realizing all the consequences, which could involve the climate, ecosystems, technology, and us critters directly.

Maybe you don't need to explain it all. It's just the way things are. Each group / person / faction has their own theories and beliefs about what happened, including the don't-breed-with-the-contaminated mantra, which may or may not be accurate. You could focus stories on the conflict between opposing views and realizations that deeply held views are not accurate. It also gives you freedom to introduce all sorts of scary things that don't have to be internally consistent because you're still discovering just what state the world is really in.

This has an added benefit: Somewhere down the line, when the series is ready to jump the shark, the new writers can finally reveal what the "true" cause was and re-focus the story (with the obligatory replacement characters) on dealing with the "real" root cause, tossing aside all prior canon as having been a big misunderstanding. :)

• Indeed, the "WTF happened?" mystery is a great one for TV. – Sandwich Dec 13 '16 at 14:07
• WTF happened is good for TV, so long as someone in the writers room knows what happened. I believe "Pulling it out of your butt and making it up as you go" hurt LOST, among other shows. – AndyD273 Dec 13 '16 at 19:35

# Toxic asteroid shower

If a big asteroid roughly headed for earth would burst apart into a massive field of millions of smaller parts with varying speed, they could go down on earth over the course of months or years. Some impacts might be big enough to create tsunamis, destroy infrastructure or cities. Others are smaller and just burn in the atmosphere. But if the asteroid contained a high concentration of a toxic substance, which spreads through the air on impact or while burning up in the atmosphere, this could lead to toxic clouds making whole areas uninhabitable.

And since the rain of asteroids is hard to predict (millions of asteroids, randomly colliding with each other on their way to earth) the only safe bet for world leaders are underground bunkers. - And you can always tune the number of impacts up and down for story purposes. There can be a week where a dense rain of big parts hits a whole hemisphere, rising toxic levels so all animals and plants die.

The explanation for the rupture of the asteroid could be ice or other elements inside of it, which got heated up by spending time in our solar system near our sun. The resulting expansion could create gas outbursts which break the rock apart.

# Two-component bio-weapon

There's a big problem with deadly diseases: hosts die off before they infect lots of other people. Also, diseases sometimes cause visible changes in the host before it's too late. Both things imped spreading.

This could be solved by using highly virulent disease that does not harm anybody and infects majority of humanity without anybody caring about that. Take a look at herpes for that part - it already fits the bill, except for the next part:

## Triggers

There would be various triggers that make the disease kill the host. They should not be restricted to a single product. Well, you can think of Unilever's products - imagine if half of these suddenly turned out to be poisonous. This way, remains of the old world would be deadly, but people would not know for sure what exactly is deadly, so rebuilding the old world would be hampered.

What makes the situation different from typical biological or chemical warfare is that if disease and trigges start spreading roughly at the same time, number of dead people will rise sharper than it would do in a typical biowarfare or chemical warfare scenario.

People will be alarmed the moment, say, 10th patient dies of that thing in a year (+- order of magnitude depending on country's development level). Since disease needs the trigger to become deadly, it will raise an alarm later, when it's much more widespread, and containing a widespread disease is much harder than stopping it in the very beginning.

Moreover, research would show this thing to be artificial which means nuclear prevenge from everyone to everyone. That will hamper further research and let the whole thing spread.

Just war. Just widespread, long, desperate war.

"I can't tell you what weapons world war three will be fought with, but world war four will be fought with sticks and stones." -Randall Monroe (He didn't say that first, but the other guy probably didn't either so at least I can misattribute with intention.)

Mash the political parts of world war one and two together, eliminate the pause in-between. Throw in some of the desparation of revolution and the tactics from conflicts with force imbalance. Add bleeding-edge modern technology. Mix and serve hot.

Half of the major powers of the world came together to form alligances against their age-old enemies and some new ones their allies hate. None of the members has the same motives, but there are plenty of motives to go around. It's not importatnt who the sides are or even what the interests are. Just that the war starts. Nuclear exchanges destroy most of the major cities in the early days. Those first to die can be considered the lucky ones. The remaining poplation learns not to bunch up and make targets, a lesson they'll live to regret. The war creeps as war does. Soon no part of the globe is safe. Tailored plagues attack the food supply and genetic markers specific to the other side's populations. Both sides claim the other side started it. In truth they were both working on it in secrect and some mis-step, some poor decision caused happened --like the cuban missile crisis but with biotech and somebody says "Screw it" and pushes the button. The conflict to escalates, an arms race of weaponized biotech emerges.

Nobody notices it happening, but suddenly there are no engineers or biologists or scientists or mechanics anymore. Everyone is busily trying to think up the next scariest weapon (I could mount a gun on that, or make poison from this). Motivated in part by fear, in part by anger and partly just caught up in the insanity of the war. Nobody even remembers what started the whole thing, or if they do it seems so trite and pointless. Those who do remember can't say it with a straight face. Seriously that? That started all this. No I don't beleive it, I won't believe it. But it doesn't matter anyway because the people, nations and alignaces that started it are all gone.

Nuclear ash, the toxic remains of the city folk and their useless things swirls in clouds, landing on the earth and water poisoning everything it touches.

Terrible diseases are released, diseases which can literally re-write your genetic code and that of your offspring (this is actually plausible with current technology a little time and some dark inspiration). They run rampant in the plants and animals of the planet. And of course Man is just the animal that lies so we are in no way immune. Nature is turned toxic by gene-mod plagues specifically designed for that purpose. Plants engineered not only to be poisionous to eat, but also to poison the air and ground. Poisoned thorn bushes not of any species, but created when a disease infects a rosebush --each one different and terrifying. The very idea of speciation is obsolete. Monsters everywhere and monstorism is contageous.

Everywhere you look there are monsters poison, radiation and death. The best thing you can do is crawl in a hole and pull the it in after you, and if you hear someone knocking, for god's sake don't open the door.

## humans vs. earth

The plausibility of this scenario depends on the following assumptions.

1. Bacteria is one of the first forms of cellular life.
2. Consciousness is born out of the complex interactions of cells responding to inputs and/or lack of inputs from their environment.
3. Humans did not evolve naturally.

First some back ground.
One of the first life forms to appear on Earth is Bacteria. Bacteria multiplies, mutates and evolves into multi-cellular forms with different sensing mechanisms. This form of life develops consciousness much like the brain as we know it today. This intelligence decides it wants to explore its environment and starts to develop complex life forms, through self replication. Ecosystems develop and eventually mobility, senses, primitive intelligences, and creatures with brains evolve. Brains modeled on the intelligence that designed them: made up of many cells which react to the environment through sensory perceptions.

Creatures with brains populate and evolve with the sole purpose of exploring and experiencing their environment.
Humanoids Appear
Some kind of intervention takes place. For unknown reasons and/or motives outside forces create Humans from Humanoids. Perhaps it is a radio active meter or a gamma ray burst, that hits the earth. The results is that Humanoid genetics are changed.

The intelligence that created the Humanoids and all other life forms that followed bacteria on the evolutionary tree, has been aware of these Humanoid to Human changes.

As it is a Super Intelligence, which acts in time frames of millennia, it takes a wait and see approach. Conflicted by the huge evolutionary steps taken by Human kind, which furthers its own goals, and the plan it set in motion, eons prior, which will no longer work within the accelerated evolutionary environment, the Earthly Intelligence does nothing. The goal of exploring the environment is more feasible now, but eons of shaping biological imperatives will have unknowable consequences. The Earthly Intelligence will watch how this plays out patiently.

Eons later the biology put in place millions of years prior takes shape. Dormant genes begin to awake in humanoids, conflicting with the intervening programming introduced from the alien source.

A pandemic of Genetic diseases breaks out. The conflicting genetics spawn mutant viruses that attack otherwise unaffected humans. The Earthly Intelligence takes action against certain genetic populations to ameliorate the damage caused by the alien intervention.

Chaos ensues.

I haven't seen any show tackle the extinction of pollinators yet (eg. honeybees). It's a real and serious threat to the world's food supply. Lack of food resources can easily lead to brush wars, which could trigger larger-scale conflicts, etc etc.

• While the strictly cereal grains are wind pollinated, virtually all legumes, fruits and vegetables are bee pollinated. Legumes also include the most useful fodder crops (alfalfa and clover) so loss of pollinators is a real problem. Total honeybee extinction might not be easily survivable. – Catalyst Dec 14 '16 at 14:56

I like a lot of the ideas that are presented here, but the way I would approach it is through warfare.

You can set up your background in a lot of different ways pre-event, but this is my thought process:

Increasing tensions throughout the world (and perhaps a few brushfire wars or international incidents) increases the military strength of the U.N., but also increases its bureaucracy. Veto powers in the security council are removed, but resolutions there require a full 2/3 agreement from the entire UN, not just the council (with the council acting more like an advisory body). The UN also raises its own military forces in the forms of mercenary soldiers that don't have loyalty to a particular government, besides the UN. This means that outright wars between member states are difficult or impossible, but "rogue acts of terrorism" from "third parties" won't be reacted to very quickly. Most nations start spending less on national defense, relying entirely on the UN's forces, or change to a more special forces model of a small cadre of elite soldiers versus a large standing army.

Most major nations now fight shadow wars, secretly funding or backing terrorist organizations to meet their ends. When a terrorist cell captures a missile silo and destroys a major city in nuclear fire, the UN takes control of all nuclear arsenals of its member states. Similar events happen for the UN to seize all biological and chemical weapon stockpiles it can access. These efforts are not 100%, but greatly reduce access to these kinds of weapons.

However, a terrorist cell, or an accident, releases a genetically modified mosquito, carrying a genetically modified supervirus. The mosquito breeds rapidly and can adapt quickly to all but the harshest environments. In most people, the virus lies fairly dormant, only slowly reproducing but not causing symptoms, until a triggering event happens (you can pick this. Stress, infection with a different disease, dehydration, whatever), but can still spread through fluid contact.

When active, the virus impedes decision-making abilities, causing the victim to fall into what appears to be a nepotistic state (picking fights, drinking and eating to excess, having lots of sex, etc), and can live for a long time, but loses sight of consequences of their actions.

What does this all mean?

1. The virus spreads quickly, and is both mosquito and human borne (explains why people are worried about "purity" when it comes to breeding").
2. Cities, or anywhere with a lot of people, are dangerous places, where, depending on your timeframe, either lots of infected people live, or have been devastated as food ran out and people resorted to cannibalism.
3. You have a strong, global organization that could have prepared or seized areas to keep its people safe (perhaps with the only surviving medical facilities capable of detecting or combating the infection).
4. The safest places to live are those where the mosquito's can't survive (extremely cold or hot areas, or extremely dry areas). They are genetically modified, so this is up to you. Hell, make them like killer bees, and have them able to mate with other kinds of mosquitos and pass on the virus and the modifications.

So I think a two prong attack.

First prong is to remove all the defenses, and an easy way to do that is with EMP's. Launch nukes on SCUDS from container ships 25 miles up over the continents and set them off. No radiation, no one dies right away (for a few minutes until the planes fall out of the sky). But civilization is effectively over.

If some multinational had an idea that it was going to happen (or maybe the CEO has read One Second After by William R. Forstchen and is now a paranoid person), and they have shielded hangers to store aircraft, which they then generously agree to use to evacuate people they see fit. They see it as their way of shaping the future.

Across the globe there is mass hysteria and a breakdown of civilization as everyone goes back to the middle ages, except that now there are to many people and no infrastructure to move things from one place to another.

In a few months a third of humanity is dead, there is no sanitation, disease runs rampant, and thousands of people are roaming from place to place to try to find what they need to survive. And then the second prong hits, when bio weapons are released and something airborne and deadly begins to spread. The ones that don't die from it become carriers as the disease lies low until it is triggered by stress caused by too many people in one area, and one of it's reservoirs within the body are the reproductive cells. This also renders them sterile.

Now 80% of humanity is either dead or infected, and so finding the healthy ones and keeping them healthy so they can reproduce is pretty important.

# Moab Inc. did it. On purpose?

As Michael Karnerfors correctly points out, how come the "important" people are all rescued by one company and not by their respective governments? Yes, you could try and handwave that away via some nod to Syndicate Wars. But let's rather have something more interesting:

Moab, UT, happens to be Earth's opposite to some Point X approximately between Île Amsterdam and Iles Crozet, but being part of the French Southern and Antarctic Lands. So a French-German company you say? What an interesting coincidence! So their base is as far away from Point X as you can get while remaining on Earth. That makes me think of the following scenario:

• They experimented with some new rocket drive (fusion drive, or even some fancy dark matter involved?).
• Knowing the high risk involved they chose the basically unpopulated French overseas territory mentioned before, and just to be safe, built their base on the opposite end of the world.
• Since their drive is the method to finally get out of our solar system in finite time, important people are invited to said base for observation.
• Of course the experiment went downhill, the sank down the ocean and caused a chain reaction by which a significant amount of ocean not only got radioactively contaminated but also vaporized (maybe after the shockwave caused severe Tsunamis all around the world).
• While some of the water remained in the atmosphere in the form of clouds (maybe enough to cause a nuclear winter), lots of it comes down again, causing massive floods (of highly radioactive water!) hours or even only minutes after The Disaster. No one is prepared, no place is really safe (except for Nuclear Shelters; whether those are also occupied or maybe were completely disbanded due to World Peace is up to you...)
• Some water was also ejected into space, thus making water (and thereby indirectly food) hard to come by.
• Did I mention the radioactive water contaminating everything?

I mentioned "on purpose", didn't I? Some of Moab, UT's involuntary guests learn about the company's awareness of the risk - who's to say they did not precisely know what would happen, and their slightly mad CEO wanted to recreate The Flood?

Food Crop Famine:

Since nobody has yet suggested it, I'll opt for going biblical, with a literal crop famine, brought on by (your choice, I'll suggest bioTerrorism gone way wrong) -- but the result is that modern varieties of rice, wheat and corn are no longer viable food crops. Suggest searching the term "monoculture." (Yes, barley is related to wheat, but I'm asserting that barley survives -- because a future with no beer is just too grim to write about!)

Interesting side effect: The old Irish diet (barley, oats, potatoes) is one (admittedly bland) way to survive. But. There just isn't enough time to grow enough seed to change farms over, before most people die of starvation -- or are eaten. Investigation of how many weeks of food reserves we really have is IMHO quite alarming, YMMV.

If you also posit a way to kill (or radically limit) electrical power and gasoline/diesel-powered vehicles, and the world won't go back to (our) normal, even when the survivors learn to eat what they can still grow. We take mass movement of foodstuffs and refrigeration for granted. (Oops!)

• Could one of the genetic attacks described in other answers be designed to go after chlorophyll-using plants? I don't know enough science to expand the idea, but it would leave the planet pretty devastated, and that much dying plant life would make the air pretty unbreathable, even before we got to CO2 poisoning. – SRM Dec 13 '16 at 19:09
• @SRM, I'm not much better than a layman in the life sciences, but I suspect that a non-chlorophyll-user (e.g. a fungus) might be made to do so. But I suspect that would be essentially unsurvivable on earth without some real handwavium. Ditto something that attacks cellulose, the primary structural basis of plants. – Catalyst Dec 13 '16 at 19:14