Jennifer adored her husband, Gerald. But one day she took a kitchen knife, went to his office and, in full view of the entire office staff, stabbed him savagely and repeatedly to death. It seems an open and shut case. Nevertheless, Jennifer insists that she is innocent of the crime - that the killing was carried out by Jane, Gerald's first wife, who died six years before.
Jennifer's bizarre defence is that at the time of the murder she was possessed by the spirit of Jane, bent on revenge. As the police and the lawyers question her, the interrogation turns into a frightening three-cornered contest - between Jennifer, her questioners, and Jane, whose turbulent presence within Jennifer's consciousness threatens her very sanity.