In 1920's England, Sarah Piper, a young woman of limited means and even less experience, confronts the ghost of a mysterious serving maid. Sent to assist a ghost hunter, Alistair Gellis, who is rich, handsome and scarred by World War I, Sarah assists Alistair as they investigate the spirit of the nineteen-year-old maid Maddy Clare, who is said to haunt the barn where she committed suicide.