The Thirteenth Floor

When computer scientist Hannon Fuller is found murdered, his protégé Douglas Hall becomes the prime suspect. Suffering from memory loss about the night of the crime, Hall must enter the hyperrealistic 1930s virtual world Fuller created. Inside the simulation, he searches for a message left by his mentor. He soon discovers that the boundaries between the virtual and real worlds are blurring, leading to a terrifying revelation about reality itself and his own identity.