The Secret is a 2007 thriller, directed by Vincent Pérez and a remake of Himitsu, a 1999 Japanese film written by Hiroshi Saitô. It is the story of a mother who dies, and whose spirit later returns in the body of her daughter, living her life in preparation for her potential return. The mother, Hannah living in the daughters body,Samantha, is stil having relations with the father, Ben through Sams body

Source: Wikipedia