The movie opens with a glass cage. Two men who apparently know each other wake up chained to either end of a table saw. The puppet thing rides in on a trike and says they have to decide whether the other guy will die, so that the big-breasted girl who is suddenly revealed to be suspended above them will live, or choose to live and let the girl die. The girl tells one man she loves him and the jilted man starts winning. Then she tells the one who is about to die that she loves him and he starts winning. Then they agree to let her die and she is sawed in half, spewing blood out of her mouth and intestines on the floor.Hoffman (Costas Mandylor) escapes from a trap which was attached to his head. He stitches himself up. Bobby Degen (Sean Patrick Flannery) is a survivor of Jigsaw/John (Tobin Bell), and he has written a self-help book called S.U.R.V.I.V.E. which is based on his experience of escaping a Jigsaw trap. He pierced his pectoral muscles with hooks and hoisted himself into the air in order to escape. He is being interviewed and with him are his best friend Cale (Dean Armstrong), his lawyer Suzanne, Nina, his public relations woman (Naomi Snieckus), and wife Joyce (Gina Holden). He and his handlers argue about how well the interview went. Nina wanted him to mention his wife so Joyce could come out on stage and he could kiss her, but Cale, Suzanne, and Joyce think it went well.Jill Tuck (Betsy Russell) who is Jigsaw's ex-wife, goes to the police and states that she will only speak with Gibson (Chad Donella). She says she has important information, but she will give it only if she gets immunity. Gibson immediately agrees to this.Some white supremacists are at an abandoned junk yard. The driver is glued to the driver's seat. His girlfriend is chained under the car with barbed wire. His friend is in front of the car, and another friend is also in a trap. A tape plays and says that the driver has judged people by the color of their skin and now he is going to learn that everyone is the same color on the inside. He has thirty seconds to rip himself from the seat so that he can pull a lever. Otherwise, the car is going to fall off the jacks, crushing his girlfriend and causing a chain reaction which will kill him and the others. He tries to reach and gets close, but ultimately is unsuccessful. The car falls on the girlfriend, then goes forward and rips up the the one friend and then runs over the second one, the car crashes and the driver is thrown through the window.Bobby is at a group of Jigsaw survivors. He gives a little pep talk and speaks to the people. Dr. Gorden (Cary Elwes) is there in the corner and he gives a sarcastic little speech about how useful these meetings are. Someone escorts Joyce to her car while Cale talks to Bobby about the creepy guy at the meeting with the cane (Dr. Gorden) and Bobby says he is at them all the time and nothing to worry about. Bobby goes out to the car and his wife is not there. Instead he is attacked.When he wakes up, he is in a cage. He is told that you and I both know that his story of being a Jigsaw survivor is a hoax. He must complete a series of tasks to get to his wife. First, he has to pull a handle which causes the bottom of the cage he is in to drop off. He is suspended from the cage over a small square of sharp objects sticking out of the floor. He swings his legs to get the cage clear of the them and jumps. He follows signs written in red which apparently contain drivel from his book. He and his handlers are in the game. First is Nina. She has a fishhook jammed down her throat and is tied up in a contraption. If the decibel level in the room exceeds a whisper, screws that will impale her in the neck advance. There is also a timer. She can't resist screaming as Bobby tries to pull out the hook. He gets the hook out at the last second but she's screaming in pain and gets impaled and dies. He says "all you had to do was shut the [bleep] up!"Next is the lawyer. She is in a trap which will impale her in the eyes and mouth unless he stands in a different machine and pushes a huge amount of weight up. He tries hard, but is unable to hold it up the required 30 seconds and the lawyer is killed.John/Jigsaw had been to see Bobby at a book signing and implied that Bobby was lying. There is a flashback where Jigsaw got Bobby's signature on a book and did not take the cover off the book. The flashback started when Brad saw the book without the jacket. Cale is blindfolded. Bobby must guide him across planks so that Bobby can get him a key that is hanging. Bobby must also go get the key. He talks Cale to a pretty close spot, grabs the key. Tells Cale to keep his hands close to his body and he will throw him the key. He counts to three and throws the key. It lands in his hands but bounces out and lands on the floor. Cale hangs and dies.There is an explosion at the junk yard. Hoffman sends an email to Gibson. A female cop traces the email to the junk yard. Gibson figures out where the game is being played and sends in a SWAT team. Back to the game. Joyce is chained to the floor. They can see each other (Bobby and Joyce). The video changes to the doll who tells him that to get to her, Bobby must pull two of his own teeth which have been etched with the access code for a lock on the door. The SWAT team hears that there is a live one and tries to get to him. They get trapped and poison gassed.Bobby succeeds in pulling his teeth and puts in the code. For his wife, Bobby must do what he falsely claimed he did in the book- impale his pectoral muscles with hooks, hoist himself high in the air and connect two three pronged electrical wires. His wife asks what this is about and he admits that he was not a Jigsaw survivor. He impales himself and starts hoisting. He has about 4 minutes left at this point. He is able to haul himself up high enough, and he gets one plug in his hand, but as he is reaching for the second plug, the hooks rip through his skin and muscle and he falls to the floor. A metal cage closes around Joyce and flames shoot up through the floor and she is burned to a crisp.Jill is in protective custody. At the junk yard, Gibson figures out that Hoffman had tapped into to the police security system. He's been watching them the whole time. He's in the control room for all the monitoring with a couple of uniformed cops. A machine gun pops up out of the floor and does a 360 while firing bullets, killing Gibson. Back at the police station, when a morgue tech opens a body bag, Hoffman stabs him in the neck. He is able to get to Jill and shoots the cop who was watching her. She stabs Hoffman in the neck and hides, but he finds her. He bangs her head on the table three times to knock her out. He ties her to a chair and puts a contraption on her head. The contraption blows up her head. Hoffman blows up the place where Jill was. As he walks out to his car, Dr. Gorden attacks him. He takes Hoffman to an abandoned mental hospital (the same one where Dr. Gorden lost his foot) and chains him there and leaves and says "game over." Implicitly, he will starve to death unless he can manage an escape.