When larcenous real estate clerk Marion Crane goes on the lam with a wad of cash and hopes of starting a new life, she ends up at the notorious Bates Motel, where manager Norman Bates cares for his housebound mother.

Having met on a train, a smooth-talking psychotic socialite shares his theory on how two complete strangers can get away with murder to an amateur tennis player — a theory he plans to test out.