This is a lovely ghost story/love story/historical novel.
Sarah Piper is a lonely soul, working in London in the years after the first World War when she gets an unexpected assignment from her temporary agency--to assist an author and ghost hunter. They travel to a small village to track down the ghost of Maddy Clare and both love and mystery ensues.
The haunting itself is quite dark and violent and she writes quite unsparingly about the emotionally turbulent years after the war. The story is excellent and the romance is lovely.
Fun fact for Downton Abbey fans: the ghost hunter Alastair is a dead ringer for Matthew Crawley and if you squint a bit, his assistant Matthew could be mistaken for a slightly more broken Mr. Bates.