From Wikipedia, the free encyclopedia.
Dark City is a Keifer Sutherland film in which aliens have kidnapped a city-worth of humans and imprisoned them in a fake city so they can study them. These aliens use memory-altering procedures on the humans nightly to reposition them at will into different roles within the fake city. Sutherland plays a human doctor who is forced by the aliens to assist them with the nightly memory alterations of the other humans.
While it was not a box office hit, and is not a popular science fiction movie, it has considerable reputation. Film critic Roger Ebert is a well-known fan of the movie, and uses it in his teaching.

