The Thirteenth Floor is a 1999 sci-fi crime thriller directed by Josef Rusnak and relatively based upon Daniel F. Galouye’s novel Simulacron-3, also published as Counterfeit World (1964). The film stars Craig Bierko, Gretchen Mol, Armin Mueller-Stahl, Vincent D’Onofrio and Dennis Haysbert. Computer scientist Hannon Fuller has discovered something extremely important, but knowing someone is after him, he leaves a letter for his colleague, Douglas Hall, in the virtual reality his company has created. Fuller is murdered in the real world and his colleague is suspected. Douglas finds a bloody shirt in his bathroom and cannot recall what he did during the night Fuller was murdered, so he enters the simulation to find the letter but is confronted with the unexpected.