Master conjurer Grey Carteret regains consciousness in a London gutter next to a concerned street urchin and not far from the body of a man murdered by magic. Some fool is hoping to use murder to raise a demon. Arrested for the crime, Grey must rely on the street urchin for help. But the lad turns out to be a comely lass, and she wants something in exchange.

Pearl Parkin, a gently reared lady struggling to survive in London's slums, sees magic as a way out of the life she finds herself trapped in. But blackmailing Grey into making her his apprentice has unexpected consequences. As they plunge into the hunt for the murderer, Pearl discovers that the things she once desperately wanted are not so important after all, and that she must risk her blood, her heart, and her very life to grasp the love she needs.