December 1703 finds Berry Grigsby fallen victim to Professor Fell's involuntary drug experiments. Her mind is quickly deteriorating under the drug's influence, and the only way to save her is a potion book that was stolen in an attack on the village orchestrated by a mysterious madman going by the name Cardinal Black. Matthew Corbett has volunteered to travel with Julian Devane, a self-proclaimed 'fool and bad man' in the employ of Professor Fell, to hunt down the potion book. They follow the trail to London, where the book will be sold at a secret auction. Matthew and Julian manage to secure a seat at the auction by masquerading as respected and feared underground operatives, but to prevail in their high-stakes mission, they will require help from a very unlikely source. Even if they are successful, their race to save Berry Grigsby will leave a trail of destruction in its wake. Cardinal Black is another extraordinary achievement from one of America's most skilled authors, and it