PhenomenaPhenomena (1985)

Jennifer Corvino, the daughter of a famous actor, has had trouble with sleepwalking for some time. Her doctor said that it can develop a split personality. She discovers her alternate personality when she stays at a boarding school that was once the home a Richard Wagner. But someone has been killing the students, and it relates only indirectly to the criminal sanitorium nearby. So it s up to the two greatest detectives the world has ever known, or should I say, unknown