Awakening from a drugged stupor, Dr. Lawrence Gordon (Cary Elwes) finds himself chained to a pipe in a dingy bathroom, with another man (Leigh Whannell) in the same situation across the room. The men are the latest victims of the Jigsaw Killer, a maniac who uses elaborate traps to test his victims' dedication to life. Given six hours, a hacksaw, and a bullet, Dr. Gordon tries to figure out a way to freedom, hoping his kidnapped family (including Monica Potter) can survive the nightmare as well. Hot on the Jigsaw's trail is Detective David Tapp (Danny Glover), an equally as insane cop who was once the victim of the Jigsaw's evil scheme.
