Essentially, I have a virus which temporarily turns people into psychopaths. This virus is being used by my antagonists to collapse a city.
I will be using a lysogenic virus which is triggered by some form of EM waves. It will limit the production of the hormone oxytocin, which is the main chemical regarding our morality (link to research).
The first infected person will be infected in a lab by a tiny dart (similar to a tranquiliser dart in terms of mechanics) which contains the virus. This person will then be released into the public. The virus can spread as per normal i.e. coughing, bloodstream, saliva etc. (not airborne but waterborne). However, once a certain radio wave is emitted from my antagonists' HQ, the darts will become 'live' and will emit the EM waves required to trigger the virus. Once this happens, the people with darts will turn into psychopaths, but so will any infected people around them (as long as they're within a short distance). Once these people have turned evil, they will be armed with darts (from the antagonists) and will attempt to infect any healthy people (as they're psychopaths so they'll want the city to collapse as well). However, once my antagonists' turn off their signal, the darts will stop emitting their waves and the infected will go back to normal (i.e. stop being psychopaths).
Would this work?
(If you need any clarifications, feel free to ask in the comments)