Superstition and murder haunt nineteenth-century Scotland in a twisting mystery by the prize-winning author of Edinburgh Twilight and Edinburgh Dusk. Spiritualism has captured the public's imagination. Séances are all the rage, and Detective Ian Hamilton's otherwise sensible aunt Lillian is not immune to their allure. But for Ian, indulging her superstitions has its limits. When members of Lillian's circle of séance friends begin turning up dead, Ian doesn't need a medium to tell him these aren't freak accidents. With the help of his friend Arthur Conan Doyle, Ian investigates, and he is soon drawn into a dark world of believers and tricksters, and a puzzling series of murders with no pattern, no motive, and no end in sight. Most alarming, the crimes conjure up the ghosts of Ian's own past, including the mysterious deaths of his parents, which have haunted him for years. As two cases converge, science collides with the uncanny, and Ian must confront truths that are more disturbing than he could ever have imagined.