Frank is obsessed with video games and teetering on the edge of a mental breakdown when a floppy disk containing the game Sanctum 3-D appears in his apartment without explanation. As he plays, the boundary between the game and his reality begins to dissolve. To stop the spiral, Frank has to descend into the darkest and most distorted places in his own mind — environments shaped by his fears, confronted head-on, or not at all.