Someone has volunteered to spend the night in the haunted room at the Darnley House. The room is sealed by pressing a unique coin, selected moments before, on the wax. But when the door is re-opened, someone else's body is lying there, the seals are unbroken, and the coin has not left the possession of the witness. Things are never what they seem in this classic Golden Age mystery, with a new twist in every chapter. A second impossible murder occurs...