A young American woman visiting her author father in London discovers that her childhood habit of sleepwalking has recurred. She has a vivid dream of witnessing a murder in a strange house - or is it a dream? A young American woman visiting her author father in London discovers that her childhood habit of sleepwalking has recurred. She has a vivid dream of witnessing a murder in a strange house - or is it a dream? A young American woman visiting her author father in London discovers that her childhood habit of sleepwalking has recurred. She has a vivid dream of witnessing a murder in a strange house - or is it a dream? A young American woman visiting her author father in London discovers that her childhood habit of sleepwalking has recurred. She has a vivid dream of witnessing a murder in a strange house - or is it a dream?