On a remote island, a troubled artist (Max von Sydow) feels his mind slipping away from him. Troubled by disturbing visions and paranoid delusions, he and his wife (Liv Ullmann) begin to suspect that the haunting memories are the machinations of a bizarre, perverted cult that reside on the other side of the island. The leader of this group (Erland Josephson) may hold the key to the artist's delusions.