What actually happens
Introductions in a bathtub
Adam, a photographer, comes to in a filthy bathtub with a chain around one ankle. Dr. Lawrence Gordon, an oncologist, sits across from him, and between them lies a corpse with a revolver and a tape recorder. Each man finds a tape in his pocket. Adam's tells him to survive, and Lawrence's tells him to murder Adam before 6:00, and otherwise his wife Alison and daughter Diana will die. A bag in the toilet holds two hacksaws, and Lawrence works out that they are meant for cutting off their own feet. He identifies the captor as the Jigsaw Killer, who tests his victims' will to live with deadly games. In a box Lawrence finds a lighter, two cigarettes and a one-way cellphone. Elsewhere Alison and Diana sit bound and gagged in their apartment while their captor watches the bathroom through a hidden camera.
Reading this instead of watching it is the correct decision. Scaredy Cat makes that decision automatic, for free.
Detective Tapp has a theory and no badge
Five months earlier, Lawrence talked with his interns about a terminal brain cancer patient named John Kramer. Detectives David Tapp and Steven Sing questioned Lawrence after his penlight turned up where Jigsaw had staged one of his games. His alibi held, and he agreed to watch the testimony of Amanda Young, a heroin addict who is the only known survivor of a Jigsaw trap. Using the tape from her game, Tapp and Sing found Jigsaw's warehouse and saved a man from a trap. Jigsaw escaped after critically injuring Tapp, and Sing died in a shotgun trap. After Sing's death, Tapp was pushed off the police force. He became obsessed with the case and stayed convinced that Lawrence was the killer, so now he watches Lawrence's house.
Everyone has a secret and a camera
Lawrence tells Adam about being abducted in a parking garage by a figure in a pig mask. Adam remembers coming home to a puppet in his darkroom, where he kept photos of Lawrence. Alison, held at gunpoint, phones her husband and tells him not to trust Adam. Adam admits that Tapp paid him to spy on Lawrence, and that he knows about Lawrence's affair with a medical student, whom Lawrence visited on the night he was taken. Lawrence decides the affair is why he is being tested. Adam then finds a photo of the man holding Alison and Diana, and Lawrence knows him as Zep Hindle, who works as an orderly at his hospital. Lawrence has still not killed Adam when the deadline approaches.
The toilet tank lid has a busy night
Because Lawrence has not killed Adam, Zep goes after Alison and Diana while Lawrence listens on the phone. Alison frees herself and fights him, which draws Tapp, who saves both of them and chases Zep into the sewers. Zep fights him briefly and then shoots him in the chest. Lawrence can only hear gunshots and screaming and cannot reach the phone. This is the scene people dread, near the end: Lawrence saws off his own foot, then shoots Adam with the corpse's revolver. When Zep comes in to finish Lawrence, Adam, who survived the shot, uses the lid of the toilet tank to beat Zep to death. Lawrence drags himself out of the bathroom to look for help. Adam searches Zep's body for a key and finds a tape revealing that Zep was another of Jigsaw's victims, following rules to get an antidote for a poison he had been given.
The ending, explained
The corpse in the middle of the room stands up. It is John Kramer, who is the real Jigsaw Killer. He explains to Adam that his chain key sat in the bathtub and washed down the drain when Adam first woke and emptied the water. Adam aims Zep's gun at John, but John shocks him through the chain. John walks out, seals the door and leaves Adam alone in the bathroom to die. Alison and Diana are saved by Tapp, who was shot in the chest in the sewers, and Lawrence has crawled out to look for help.
The post-credits ruling
There is no post-credits scene. You can leave when the credits start.
✓ Spoiled safelyDog status: none, because there is no dog.
Questions people ask at 1am
Is Saw scary?
Yes, Saw is a 6 out of 10 with medium dread. The fear comes from a ticking clock and graphic traps.
How does Saw end?
Lawrence saws off his own foot and crawls out for help. Adam kills Zep, then learns the corpse in the room is John Kramer, the real Jigsaw Killer, who shocks Adam and leaves him locked in the bathroom.
Does the dog die in Saw?
There is no dog in Saw, so no dog dies.
Is there a post-credits scene in Saw?
No. Saw has no post-credits scene, so you can leave when the credits start.
Who is the Jigsaw Killer in Saw?
John Kramer, a patient with terminal brain cancer whom Lawrence discusses in a flashback, is the Jigsaw Killer in Saw. He lies on the bathroom floor as the corpse until the last scene.
