Philip (Sam Claflin), due to inherit a country estate in 19th-century England from his recently deceased guardian, grows convinced that the man’s widow, his cousin Rachel, might have killed him. But he is nonetheless surprised and then entranced when Rachel (Rachel Weisz) arrives for a visit. Thus begins a mostly polite round of head games as Philip and Rachel flirt and spar; as recounted from Philip’s point of view, we, like him, never have a clear idea of the enigmatic Rachel’s intentions. Roger Michell’s film is adapted from Daphne Du Maurier’s novel, and while it has some broody people and quiet tension, it never really achieves the more entertaining heights of a nervy gothic thriller. It has good actors, truly lovely Cornwall landscapes and the appeal of a genteel parlor drama, but alas, it is a bit too dull and ultimately unknowable for its own good.