- Directors: James Wan
- Producers: Gregg Hoffman, Oren Koules, Mark Burg
- Writers: James Wan, Leigh Whannell
- Genres: Horror, Mystery, Thriller
- Actors: Leigh Whannell, Cary Elwes, Danny Glover, Monica Potter, Michael Emerson, Shawnee Smith, Tobin Bell, Dina Meyer
Photographer Adam Faulkner (Leigh Whannell) awakens in a bathtub full of water, at one end of a grimy and disused bathroom. At the other end is Dr. Lawrence Gordon (Cary Elwes); both men are chained by the ankle to the plumbing pipes. A corpse holding a revolver and a microcassette recorder lies on the floor between them. Lawrence and Adam each discover tapes in their pockets labeled “Play Me”. From these tapes, Adam is told that he must escape the bathroom, while Lawrence is told that he must kill Adam before six o’clock, or else his wife and daughter will be killed and he will be left to die where he sits. They find hacksaws, though neither is sharp enough to cut through the chains. Adam breaks his and throws it away in frustration. Lawrence realizes that the saws are not meant for the chains, but instead for their feet.
Lawrence determines that their captor is the Jigsaw Killer, so named due to his practice of cutting pieces of skin in the shape of a jigsaw puzzle piece from his victims. The name is a misnomer, says Lawrence, as he never directly murders anyone and his intentions are for his victims to survive with a better appreciation of life. In a series of flashbacks his previous victims are presented, including his only known survivor up to that point, a highly traumatized heroin addict named Amanda Young (Shawnee Smith). She believes that her experience in the test, in which she risked having her jaws ripped apart, has made her a better person.
Adam searches Zep’s body for a key, but finds another microcassette player instead. Adam learns that Zep was only a pawn in Jigsaw’s game, following rules laid down for him in order to get the antidote for a slow poison he had been given. The “corpse” in the middle of the floor slowly rises to its feet, peeling some bloody makeup from its face and revealing itself as John Kramer, the Jigsaw Killer. Adam reaches for Zep’s dropped pistol, but Jigsaw stuns him with an electrical shock from a hidden remote control. He tells Adam that the key for his chain was in the bath, which we saw Adam accidentally pull the plug out of with his foot at the beginning of the film. Jigsaw then flicks off the lights and shouts “Game over!” before slamming the door and sealing Adam in the bathroom.