When a workman is pushed and hissed at by something invisible on the stairs of her family’s 150-year-old townhouse, Jeanne Stanton must confront the possibility that a ghost inhabits. She proceeds in the way any former Harvard Business School case writer would: she embarks upon a rigorous search for proof of the ghost’s existence and identity, exploring the literature and lore of ghosts; the practices of mediums, psychics, and “ghost busters;” and the various attempts that have been made over the decades to verify ghostly sounds and sights through scientific methods. After visits to a psychic provide insights but not proof, Stanton enters the equally mysterious realms of physics and neurology, hoping science has answers. Notables encountered during her research efforts include Henry James, Arthur Conan Doyle, Oliver Sacks, and Sigmund Freud, the latter a colleague of her home’s original owner. Wry and witty, Stanton takes time out to laugh at her own futile attempts at ghost detection—spending a sleepless night in an allegedly haunted bedroom, creeping along the edges of rooms in search of cold spots—along the way. Determined to get to the bottom of the ghost business, Stanton wavers between skepticism and belief, searching for definitive evidence—and almost failing to find it. Almost.