Two men wake up to find themselves shackled in a grimy, abandoned bathroom. As they struggle to comprehend their predicament, they discover a disturbing tape left behind by the sadistic mastermind known as Jigsaw. With a chilling voice and cryptic instructions, Jigsaw informs them that they must partake in a gruesome game in order to secure their freedom.
An Oxford Medical School graduate takes a position at a mental institution and soon becomes obsessed with a female mental patient, but he has no idea of a recent and horrifying staffing change.
Child psychologist Carter Nix is a loving and caring family man, but under this appearance lies a dark and troubled past. Grappling with the consequences of this past on his own psyche and the influence of his returning father and violent brother Cain, Carter becomes involved in a series of murders and kidnappings. Meanwhile, his wife Jenny rekindles an old love affair, placing herself in the crosshairs of her increasingly unstable husband.
Now confined to a mental hospital, young Kirsty insists her supposedly dead father is actually stuck in Hell following his wife’s betrayal. Few believe the young woman’s lurid stories aside from the thrill-seeking Dr. Channard. Kirsty is undeterred and, with the help of a fellow patient, heads to Hell for a rescue.
A lone drifter suffering from partial memory loss accepts a job to look after a psychologically troubled woman in an abandoned house on an isolated island.