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.

Hedonist Frank Cotton finds a mysterious puzzle box that summons the Cenobites, who open the doors to a dominion where pain and pleasure are indivisible.