Amid a gilded age of convenience and excess, the capital city of Berbiton is still occasionally assailed by old-fashioned ghouls and rustic imps who prey upon the poor and powerful alike. Whenever the constabulary and giants of industry fail to rescue the browbeaten, it falls to the Hexologists, Isolde and Warren Wilby, to answer the fevered call.

Isolde Wilby enjoys a mystery much in the way that a terrier relishes a rat. Unconstrained by social nicety and compelled by a ruthless curiosity, Iz depends upon the tempering presence of her husband to keep her fed, rested, and friendly with persons she might otherwise overrun. Theirs is a partnership fueled by passion and a shared devotion to higher ideals.

Isolde and Warren’s preference for smaller clients is finally trumped by the specter of the greater good. When they are approached by the royal secretary and told that the king pleads to be baked into a cake—going so far as to wedge himself inside a lit oven—the Willbys quickly find themselves embroiled in a mystery that imperils a nation and challenges their cherished autonomy.