Anne is sent by her adoptive parents to spend the summer with a couple who live near a tidal marsh, where she meets Marnie, an enigmatic child her own age living in an apparently abandoned mansion. The two form a passionate friendship and Anna is drawn into Marnie's dream-like world and tries to solve the mystery of her past. Animated drama from Studio Ghibli, with the voices of Hailee Steinfeld and Kiernan Shipka