A traveller by the name of Crossley forces himself upon a musician and his wife in a lonely part of Devon, and uses the aboriginal magic he has learned to displace his host.
Bored while officiating a cricket match at a psychiatric hospital, Crossley tells Graves (a visitor) the tale of a mysterious stranger (also named Crossley) who invades the lives and house of a local musician and his wife. The stranger claims knowledge of real magic, which he uses to displace his host and dominate his wife. The musician must find a way to combat Crossley and his seemingly implacable powers. Graves doubts Crossley's claim that the story is true, and begins to believe that Crossley is actually one of the patients.
A madman tells the story of how, using Aboriginal magic, he forced himself upon a musician and his wife in a lonely part of Devon, and displaces his male host.
