Sam Enfield takes over when Madame Marie – the previous host of this broadcast for witches and enthusiasts of the arcane – disappears. As if it wasn't hard enough keeping up with calls for advice, ominous forecasts, and strange recorded messages, Sam soon discovers there are things more sinister than ghosts lurking in the Spirit Box Radio studio. As the mystery unfolds, it becomes clear that Sam was always more than a lowly PO Box Boy, and in the Enfield family, secrets run deeper than they might at first appear.