The story picks up immediately after the events of Saw IV . Detective Mark Hoffman is hailed as a hero for "rescuing" a young girl from Jigsaw's traps. In reality, Hoffman has spent years working as Jigsaw's apprentice—a relationship that began after he used a Jigsaw-style "pendulum trap" to murder Seth Baxter, the man who killed his sister. The Fatal Five

Believing he has trapped Hoffman, Strahm pushes him into the box and locks it. However, the box lowers into the floor while the walls of the room begin to close in. Strahm realizes too late that the coffin was his only means of survival—Hoffman remains safe inside the floor while Strahm is crushed to death as the film ends.

While Hoffman cements his position within the police department, five seemingly unrelated strangers—Brit, Mallick, Luba, Charles, and Ashley—wake up in a sewer. They are forced into a series of lethal tests where they must make grueling sacrifices to advance.

Released in October 2008 and directed by David Hackl, continues the legacy of the Jigsaw Killer through his secret apprentice, Mark Hoffman.

Suspicious of Hoffman's miraculous survival, FBI Agent Peter Strahm begins a rogue investigation. He uncovers Hoffman's past and realizes he is the new Jigsaw. Strahm follows Hoffman to a hidden basement, where he finds a large glass coffin.

Throughout the game, the victims fight and sabotage each other to be the "sole survivor".