Mike Church (Sir Kenneth Branagh) is a Los Angeles private detective who specializes in finding missing people. He takes on the case of a mute woman named Grace (Dame Emma Thompson), who is suffering from a total amnesia and doesn't even know her name. She keeps having nightmares involving the murder of a pianist named Margaret Strauss (Dame Emma Thompson) by her husband, Roman (Sir Kenneth Branagh), in 1949. In an attempt to solve the mystery about her identity and her nightmares, Mike accepts the help of antiquary Dr. Cozy Carlisle (Robin Williams), who arrives to offer his services as a hypnotist. The hypnosis sessions soon begin to reveal some surprises.