London, 1761. St. Mary's of Bethlehem, a sinister madhouse, is visited by wealthy people who enjoy watching the patients confined there as if they were caged animals. Nell Bowen, one of the visitors, is horrified by the deplorable living conditions of the unfortunate inhabitants of this godforsaken place, better known as Bedlam.

A shipwrecked Don Rainsford washes up on a homicidal big-game hunter's Caribbean island where the madman hunts human prey for his personal island habitat.