A cozy, small apartment with no way of getting out of it. The window is just a one way mirror.
An omniscient force, that either sends in an object that gives them more chances of getting out every week. Sometimes it sends a new person.Six individuals, no memory of how they got here. Now, the omniscient entity sends the group one final object. A gun. A gun that must be used to kill one member of the group. If they do that, they're allowed to get out with a clean slate.

I would love some feedback on this idea cause I'm considering to make this into a comic.