Vault 1718: A vault full of people that would normally be locked up inside insane asylums, straitjackets and all. And all of these lunatics are sealed inside the vault with no hope of exit, little food and water, and they are also exposed to subliminal messages over the loudspeaker encouraging cannibalism.
Meanwhile, the only sane person inside the vault is inside a secret compartment full of food and water, but he cannot leave, as the lunatics are armed with high-powered energy weapons and the vault is locked shut. Plus hearing the lunatics babble on and on is starting to wear away at his sanity.
Through a hole in the wall of the compartment the man can spot what looks like a secret exit out of the vault, and only he knows about it. So the question is, what will the man do? Risk his life to escape the vault full of cannibalistic lunatics, only to find himself in a nuclear wasteland bereft of life, or enjoy the comforts of the vault until the sound of the lunatics drives him insane?