It's modern day, and aliens travel to Earth (cloaked so that no one is aware of them). They send huge robots down to a town or city and manage to kill everyone there, apart from a single survivor.

This survivor manages to make it to another town, where the first thing he does is run to the police station to tell everyone there that he has witnessed the destruction of the town/city and managed to escape.

However, everyone looks at him as if he is crazy. They say "if that had happened we would have heard about it!"

So what would be the best way for the aliens to ensure word isn't spread about the destruction of this town/city?


  • The aliens have almost omnipotent powers with their advanced technology compared to ours. They can do things such as cloaking, holograms, blocking satellite/radio/internet communication and anything else you can think of that technology can do now or in the future. However, they cannot erase memories to make everyone think that the town/city never existed.

  • The ruse only needs to go on for approximately 24-48 hours, after which time they have already destroyed a number of smaller towns/cities in order to make bases for themselves where the towns/cities once stood. After this time they will drop the stealth tactics and branch out from these bases to attempt to subjugate the human race.

  • They have studied Earth for a while and understand our technology limits and humans themselves, so they wouldn't leave any means to be discovered by accident, until they're ready to reveal themselves.


  1. What would be the best way for the aliens to make sure no one has noticed these towns/cities have been destroyed? They will have to take into consideration people who live there all of a sudden not communicating with out of town friends/family, people who would drive through after the town is destroyed potentially walking into the ruins.

  2. What size towns/cities would be big enough to have bases of operations but small enough to not attract attention to the general population? Could it happen to a small city or would it have to be small villages? What countries could they be in that it would go unnoticed?

  3. How would they subvert things such as satellites noticing this has happened?

To clarify: Perhaps I put too much information into the question, so I will summarize what I am asking.

If you had infinite technology, how would you conceal the fact you have captured a town and all of its people without alerting anyone for 1-2 days?

It's OK if people start to suspect something is wrong (like a friend going to voicemail who usually picks up), but without anyone jumping to the conclusion that the planet is being invaded.

  • $\begingroup$ most of the trans-ocean communication is through underseas fiberoptic lines. $\endgroup$ Commented Apr 13, 2015 at 10:39
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    $\begingroup$ I think the real problem with this question is that if the aliens have such powers, how come there's a survivor? $\endgroup$
    – Fhnuzoag
    Commented Apr 13, 2015 at 11:18
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    $\begingroup$ Why take over a town at all? If all you want is a base then pick a random bit of wilderness or isolated farm and take those over. Much simpler and there is no real reason for aliens to want people... $\endgroup$
    – Tim B
    Commented Apr 13, 2015 at 12:27
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    $\begingroup$ @Mike.C.Ford They have interstellar travel, cloaking devices, etc. I really double our road network is of any interest to them at all. $\endgroup$
    – Tim B
    Commented Apr 13, 2015 at 13:40
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    $\begingroup$ All they would have to do is wipe out Bielefeld Germany. Everyone already knows that it doesn't exist, so half their work is already done. $\endgroup$
    – AndyD273
    Commented Apr 13, 2015 at 15:23

15 Answers 15


3) Satellites: easy to fool with an image perpetuated from just before the attack. Project it above the site so the satellites perceive it as the actual surface. Only has to last 24-48 hours. They may want to spend 24 hours hovering to take a full noon-to-noon cycle to cover the night changes in artificial lighting.

2) Choice of country can make all the difference. The more wired the country, the more mobile the population, the more outsiders will notice the lack of Facebook updates or be more likely to drive to through. It has to be off regular rail or air service, only a weekly or biweekly at best.

Of course, villages are easier. But I think you want the largest place they can get away with, right? Otherwise they could avoid destructions and set up in the middle of uninhabited nowhere at leisure. So what are the human facilities they need out of the village/town that they can't get at some deserted lake in northern Canada? How is a rural village in Nigeria or a small town in the Philippines any better?

1) Timing is critical. If it's a ski resort, don't hit on a February weekend. Look for when it is most deserted, with the fewest outsiders coming in. Not on a convention weekend. Major cities and capitals are off the list. I'm seeing a seaside resort in off season, still cold if not snowy, and a major storm (blizzard, sleet, rain) may have knocked out communications normally in the area.

This question is going to take people from all over piling on with their suggestions of a good town in their area that suits the shopping list. This could probably be best as a separate question: this is my set-up; what towns in your knowledge would you suggest? Otherwise, you get to invent a place.

Some small towns get most of their traffic on weekends, with the weeks isolated. Some act as bedroom communities, with lots of commuting on the weekdays but people stay home and mow the lawns on the weekend.

Do you have a positive or negative preference in continents or countries for the setting? Like, you just don't think you can handle the cultural differences of setting this in the USA or Mongolia or wherever?

Obviously, this target must be within fleeing distance of the second town where the survivor goes. On foot, maybe thirty miles in two days (assuming he isn't an ultra-marathoner). On horse, maybe seventy miles if he got a good one. On bicycle? Moped? Motorcycle? What will he find to use?

However, everyone looks at him as if he is crazy. They say "if that had happened we would have heard about it!"

At which he tells them to call someone there. Frankly, if destruction of communications is the first step he tells them about, there isn't any reason they would have heard about it.

Hmm. The aliens also need to keep the sky above the town lit. Neighboring places might wonder at the sudden lack of light pollution, especially on a cloudy night. Hilly/mountainous terrain is the aliens' friend.

At this, I suggest the aliens create a major rainstorm over the larger area a couple days before to keep humans inside on the weekend, busy pumping out their basements, swearing at localized flooding, not looking at the sky, not wanting to drive anywhere unnecessarily, and blaming any communications or other blackouts on the weather.

Hope this helped!

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    $\begingroup$ I really like the manipulating the weather conditions thing, and the off-season seaside resort, that way they have access to the sea as well as the land and air. Or a mountain town/village could have passes closed due to bad weather so no one goes up there. The guy is there on business, so the location doesn't really affect the character. One idea I had for if someone rang anyone in the destroyed town was an automated reply using the person's voice and generic answers in conversation, that only someone close to them would realize they were replying strangely. $\endgroup$ Commented Apr 13, 2015 at 11:47
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    $\begingroup$ In fact, a place that's very wired but unconvenient to access physically would be the best bet - the aliens should have no problem spoofing a bunch of facebook posts and they could even answer the emails/sms/calls of concerned relatives with vague replies. It doesn't require that much technology - even the current USA/Russia/China secret services probably might pull it off for a day or two if they had a sufficiently huge reason and some time to prepare; no issue for powerful aliens. If noone is visiting, a bunch of fake selfies of your acquitances there would be enough to delay any doubts. $\endgroup$
    – Peteris
    Commented Apr 13, 2015 at 18:09
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    $\begingroup$ You might benefit from having them invade right as a large storm hits, and starting by cutting power to a huge area. Put their power plants out of commission and make it look like an accident- that way no one would notice a city not responding to communications. They might still be worried, but with dozens of towns experiencing a blackout simultaneously, the complete silence of one of them wouldn't be noticed amid the near-silence of the rest. $\endgroup$ Commented Apr 13, 2015 at 23:56

So the aliens sneak into town as quietly as possible. They have personal cloaking, as well as cloaking on their mothership. They go house to house, quietly unlocking the doors, and throw in knockout gas to subdue the people inside. Knockout darts are used for people that are out and about.

After the occupants are knocked out they scan their brains and digitize their personality and memories, then kill them.

They tap into all the communication lines, but leave all the infrastructure alone. All the street lights work, lights are on in some of the homes but not enough to be weird, etc.

Anyone arriving at the town is allowed in, and when they stop and get out of their vehicles they are surouned by cloaked aliens, knocked out and digitized.

When the lone survivor gets to the neighboring town he runs to the police station and tells the officer on duty that everyone is dead. The officer calls the police station of the captured city, and gets one of the digitized police officers on the phone who assures him that there are no aliens and everything is quiet.

The survivor leaves the police station, calls one of his friends who he saw killed, and the digitized version answers the phone, wondering why he's being called at that time of night, and answering all questions naturally. Now the survivor is doubting his own sanity.

The weirdest thing is that his one friend who NEVER answers his phone or responds to text messages is suddenly responding promptly.

Bonus if he's able to convince one of the digitized personalities that they are dead, and then use them as an ally against the aliens...

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    $\begingroup$ Nice one. But if they scanned the personality and memories of his friend, they know not to answer the phone, right? $\endgroup$
    – Vince C
    Commented Apr 14, 2015 at 8:21
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    $\begingroup$ @VinceCgto The people are digitized, as if stored on some computer. They're then hooked up to the phones, as it were, so they're "forced" to answer the phone. $\endgroup$
    – Pimgd
    Commented Apr 14, 2015 at 9:20
  • $\begingroup$ @Pimgd Right, that's what I was going for. Like suddenly Grandma is liking the pictures you put up on facebook at 3 A.M. Poor Grandma :'( $\endgroup$
    – AndyD273
    Commented Apr 14, 2015 at 13:57

Coordinated attack on whole country

Example: Czech republic (I love attacking my own country)

With unlimited tech, it should be easy to attack all people in given country. You just program attack bots.

And if you choose proper time of such attack, which should be 4 AM (source: I worked at Telco and at this time all major releases were done), you will have easy job locating the people.

Also if someone managed to escape, they will be really not trustworthy because they managed to escape from some party, so most probably they will be under influence of alcohol (imagine someone shouting at 4:30 AM to police that whole country was attacked by aliens. The police will most probably look them up and buy some more time for aliens)

After such attack, you are only left with tourists and people passing by. Easy to fool them.

Problem with unlimited tech

Say I have programmable kill bots. And I have loads of time and really advanced technology...

What stops me from sending 8 billion of them in one huge coordinated attack?

  • $\begingroup$ I like the 4am tactic, when the fewest people would be awake, so no one would notice it had happened. And when I come to write it they probably won't have unlimited tech, just as much as they need to pull off the destruction and capture of the town. $\endgroup$ Commented Apr 14, 2015 at 9:08
  • $\begingroup$ There are even smaller countries in Europe than Czech Republic is. If you attack the whole country, you get advantage of controlling people and information (the police is going to call foreign ministry for example. And it is easy to put one alien here to answer it and say "everything is fine. Move along") $\endgroup$ Commented Apr 14, 2015 at 9:18

Another classic approach: Set up some plausible situation where nobody would wonder about what he's seeing.

Simple example: Spread the news (spoofed TV, Internet, ...) that some industrial accident happenend at the town, which both destroyed communication infrastructure and made complete quarantine necessary for a day or two.

Now if someone claims there are aliens at work, every well-informed person will tell him - that he's crazy and that what's really going on is what was on the news.

This could work for a single town or city, but of course not so well if a couple of those accidents happened all over the country at about the same time...


With advanced technology, a convincing simulation should be possible. Redirect all communications to the simulation and those outside the town would feel like they still are in touch. The simulation would be good enough to reproduce the responses of individuals that once lived in the town, so that the character that survived would have the surreal experience of phoning a friend or relative that he knows is dead.

The alien base would replicate the structures and electro-magnetic signature of the town so that light, radio, financial transactions, etc. are still continuing as normal. The surviving character would then be challenged to prove to outsiders (and maybe to insiders, the AI simulations themselves) that it is a simulation.

If the ruse only needs to last 48 hours, then things like airplane or bus traffic could work on a "roach motel" model: travellers can check in but they never check out. Anyone who makes it to the town is destroyed and the simulation takes up their communication with the outside world (they can still call their family and let them know they are delayed in this town).

Sub-plots could include the fact that grandma suddenly knows how to work her phone a whole lot better, or that the town is trying to lure certain strategic individuals to travel there so they can be destroyed or captured.

  • $\begingroup$ Sub sub plot: each persons personality and memory are digitized before they are killed, so that each person can respond naturally. $\endgroup$
    – AndyD273
    Commented Apr 13, 2015 at 15:25

I have a town in mind that could be a great candidate for this total destruction that would go unnoticed for a week. I lived in this town so like the aliens I have studied it and think it is a good town to destroy for a base.

But a bit of a paradox comes up. Why would they take over a town? What benefit does a destroyed town have for them over a isolated spot? It does not seem they benefit from taking over a city. A town or city seems to have a higher risk of discovery then an uninhabited spot, just a thought.

The town I have in mind is Ely Nevada. The link is to search result of Ely.

Ely is a small isolated town, with a small population of about 5000 people. It is a town at high altitude, 6400 feet. The town is at the intersection of two highways, NV 93 and Highway 50. In all directions it is 80 to 160 miles to the next gas. It is over two hundred miles to the nearest Walmart. If the aliens need super low priced shopping the are out of luck.

Ely has very little trade. It has a mine that truckloads of ore are moved out of daily. Businesses that have deliveries like a super market, McDonalds and of course package type stuff like postal. It also has an Internet trunk line (backbone) routed through town. The roads have very little traffic, I would speculate hundreds of cars and trucks each day, not much more. Tourist trade is light, mostly hunters in season and people just passing through on their way to someplace else. There is only one scheduled flight in each day, which is often cancelled because no one is flying in. (Ely airport has the highest per passenger flight subsidy in the nation, over $3000 per passenger.)

A weather event like a snow storm would bring traffic coming in and out of town to a standstill. Add as a consequence of that event a power outage, that puts cell phone service down and knocks out the internet and you have enough diversion to keep outside suspicion down to a very reasonable level. Outsiders might get suspicious, but it is not likely that suspicion would gain enough momentum for investigation to verify something is wrong within your time frame of 48 hours.

The people that might be the people that raise the invasion by aliens flag, would be the crews coming to repair the lines, and clear the roads, would put off coming until the storm mostly passed. In Ely the highway station that keeps all the snow plows is located in Ely, so not much out side help would be coming in. Same is true for power. Nobody will be coming in force from the outside.

There is no chance of someone getting out on foot, it is simply too far to the next town. Even a motorized escape by land would be difficult. A snow mobile would not have the hundred plus mile range needed to get to the next town, and since the next town in all directions is at least two thousand feet lower, it is likely they will run out of snow to trek even if they had range. Most other vehicles would have a difficult time getting out cross country. At any rate the trip cross country in snow would be very long, twelve hours more or less. Word might get out from a ham radio hobbyist with a generator.

Even if the Aliens were discovered in a matter of hours, it would still be a matter of days before anything but an airstrike could be mounted to remove the aliens. It would be a good bet that the Aliens would be able to defend against any kind of conventional air attack. All the major airbases, Nellis at Las Vegas, Indian Springs, and Hill AFB near Salt lake, are hundreds of miles away. Even an emergency air response would take awhile.

Ground response, the army would take days if not weeks to mount and deploy to the area. Even modern armies do not move at highway speeds. The army would be very exposed on the long highways they would be coming in on, making attacking the convoys easy for the aliens.

Aliens could take and hold Ely easily. Aliens would have plenty of time to mount a defensive posture before any kind of force could be bought to bare.


Do the people have to be killed at the moment of invasion?

Instead, one evening everyone in the sleepy town/city goes to bed, except the protagonist who is outside the city limits indulging his vice/exploring/doing some science (pick something that fits their character). Then the aliens transport the entire town to a habitable planet somewhere nearby. This transportation is not traumatic nor is it particularly noticeable, except to our poor protagonist who was not in the transport zone.

The aliens, having supremely advanced technology, set it up so the foreign town is still connected to the rest of the world somehow, and set up a projection (or a duplicated town) in the space left by the old town - this projection could even be a live video feed of the real city if aerial reconnaissance is an issue). Now there is no difficulty, and depending on how crazy you are willing to let the protagonist feel, cops could call the city and get that cities police station reporting everything is fine.

Once the aliens are ready to drop the veil they can easily annihilate the other city(s) (or leave them alone if wiping out humanity is not the primary goal). The one remaining issue would be anyone wanting to leave town - but either you use your handy-dandy teleportation technology to allow that temporarily (again...best used if you want your protagonist feeling crazy), or you have tragic accidents befall the towns folk. If the town is isolated enough (one road in/out), you only have to "blow out the bridge" or similar and it practically takes care of itself.


The large robots from the initial post could be the clean up crew. Nano technology is interesting... Drop self-replicating geocentric nanobots into the drinking water or via an air delivery system, and the bodies could dispose of themselves. The large robots would simply be used for the construction of the base. Think of it as A.T.O.M. nanobots meet drones, with an alien omnipotent evil spin.


Control the weather.

In places where inclement weather occurs, your Aliens create the weather system. In Florida, a Cat 4 Hurricane rolls through. Not big enough to require evacuation, but enough to bring down communications. Nobody knows why the weather forecaster can't connect with the satellites! The devastation from the hurricane prevents emergency access through, and also masks the devastation from attacking and killing people.

One overly cautious person, however, has a very deep, old storm shelter. The aliens could have detected it, but didn't think they needed to look that deep. When she/he finally stumbles past the wreckage and tells the emergency vehicles that everyone is gone, they don't believe him. A Cat4? And this is Florida: they know how to handle hurricanes!

A day later, a really bad snow-storm is ripping through Germany and...


If it's done quietly why would anyone have heard of it? You don't need vast alien tech to accomplish this.

How about method that could be used (albeit quite expensive) with human tech:

Infiltrate the town. Release a colorless, odorless gas that is a mild sedative--the intent is not to knock people out, but rather make them tired. Slowly pump up the dose until everyone goes to sleep of what they think is their own free will.

People without something essential to do will go take a nap, this will reduce the demand on others with more essential jobs so they'll be freed up to take a nap and so on.


The aliens could scan a town over a couple of days and play back the activity as a hologram. Any vehicles leaving the town could be projected as a hologram out to a distance determined to be out of range of observation by people arriving. In the mean time the area scanned would be incinerated to a depth of +/- 500 meters. Any vehicles entering the town would be instantly added to the hologram showing their movement to a side street to prevent further observation by those outside the edge of the hologram. The vehicles entering the town would obviously plummet to the bottom. Any telecommunications errors would be handled by their respective services i.e. subscriber could not be found to we are experiencing technical difficulties at this time. The aliens would have the choice of letting the people incinerate with the rest of the town or to teleport them to the mother ship to probe to their hearts content.


Make an even bigger, more interesting, more conventional looking disaster somewhere else. For instance, drop a meteor on a major city, or start a tsunami that floods a coast with a large population.

Have a good reason for the disaster to explain dropped communications to your new home base town, and have a way to sweep up stragglers who might stumble upon your new construction.

  • $\begingroup$ In fiction they have used viruses to keep people out of an area for a while. $\endgroup$
    – Ras Fred
    Commented Apr 13, 2015 at 20:59
  • $\begingroup$ What kind of ways would you suggest? Consider editing them into your answer to make it even better. $\endgroup$
    – ArtOfCode
    Commented Apr 13, 2015 at 22:05

It is probably not very hard to keep the ruse up unless people already suspect something fishy is going on. If you call your friend in the next town and he doesn't pick up the phone, then "oh no, aliens must've invaded and killed him" is probably not going to be your first thought.

And honestly; can you be absolutely sure that the next town over is still there? What are you basing it on? Most likely on the fact that you've not yet heard anything that would suggest it isn't. And if you heard such a thing, it would probably be because a news station would tell you, right?

So really, to keep the ruse going for 24/48 hours, you only need to do two basic things:

1) kill all people who get direct visual confirmation of trouble

Yeah, that's anyone who sees what is going on. Whether a traveller, or an aircraft passing over close enough, or whatever. Since you can't mess around with what people see, you just need to terminate their ability to communicate it. You'll have to be fairly quick and might want to drop something that cuts connection to common communication methods (ie; disrupt the local internet and phone system)

2) make electronic systems pretend that the town is still there

For starters, scan the local area internet and try to replicate their social and other media. Facebooks continue to update, news outlets still post news, maybe even text messages still get a basic response. Doesn't have to be super accurate, just not obviously fake. The harder part is fooling some of the other systems in place. If you take down an aircraft, you'll have to feed data into flight control to make it appear to still be there. Then you redirect the plane into the ocean after a while. Before anyone figures out where the plane really disappeared, the 48 hours will be up. Likewise, you'll need to fool any active satellite feeds of the area (if they exist) and you need to make sure you don't trigger any other warning systems (seismographs going funky because you bring down the kill-o-bot might cause a lot of unanswered phonecalls, for example)

But once you do that, you basically have no information coming out to make people doubt that something is wrong. You can easily keep that going for a day or two, since that's a very short amount of time.

(Assuming you pick your target somewhat wisely. This will not work if you make an entire metropolis disappear, but it will work for many small villages.)

So to TL;DR:

  • kill anyone who figures it out visually
  • keep outputting the electronic signals of the location
  • nobody will get suspicious for the first few days

Assuming that your aliens have some significant powers, there are some better options than just shutting down communications to one town. Assuming that these aliens have the power to do so, it would make more sense to start taking out communications infrastructure to the point where it doesn't seem unusual for this town to have suddenly disappear.

One option that occurred to me was to either induce a large solar storm, or to wait for one to occur naturally. Solar storms tend to knock out everything from communications satellites to the power grid, and so losing communication with a large area is still conceivable.

Obviously, people will know that something is happening, but most rational people would blame it on a more scientific explanation than aliens.


The clarification really helps.

Assuming even mildly advanced technology, knocking out a town without anyone noticing is trivial. You just kill everyone in their sleep during night, that's it. Maybe one or two late night phone calls will be interrupted, but that won't raise a general alarm.

Communication is the key, of course. However, in many parts of the world, occasional failures in the communication networks are still so common that a 1-2 day black-out would not cause a national alarm. That's why knocking out a town is much easier than knocking out a city (and it makes it much more believable that there's just one survivor).

Depending on what exactly you mean by "without anyone knowing", however, the #1 secret trick to covering up pretty much anything is plausible deniability. Knock out the town and inject fake data that a blizzard or flood or hurricane or whatever the common local desaster is has knocked out all the communication lines (even mobile phone networks ultimately go into cables).

That way, people know that something is up, but they don't know the whole town has been knocked out. If that satisfies your definition of "without anyone knowing", it's the easiest way with the least amount of handwaving.


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