Married college professor Michael Lane falls in love with one of his students and hatches an elaborate scheme to dispose of his wife, Elizabeth. His murder plot goes as planned. However, he soon receives an anonymous note: "I know what you did, murderer!" Prof. Lane frantically tries to discover who knows his secret...
Patrick O'Neal
as Michael Lane
Angharad Rees
as Stella Mason
Michael Kitchen
as George Newton
Gerald Sim
as Peterson
Gary Watson
as Inspector Rush
Patricia Donahue
as Elizabeth Lane
Terry Wright
as Detective Constable Waters
