Prince Honoré, a talented Spiritualist medium, bursts upon the scene and becomes the idol of London Society. But at one of the prince's séances, a sitter is murdered. Bertie Hawkins is called in to investigate and checks on the backgrounds of all those involved. Bertie's cousin arrives unexpectedly from Yorkshire and inveigles his way into the investigation, becoming enamored of one of the female sitters and getting in Bertie's way at all turns. There is consternation when the medium himself is murdered by mysterious means. Bertie and Arnold are finally able to make sense of it all and to reveal a most unlikely suspect as the murderer.