Maeb Langtofte is lucky, she knows, to have gained a position in the household of the Earl of Pengraic—one of the most powerful men in England, a man whose holdings rival even King Edmond’s. She is lucky that his wife, Adelie, whom Maeb serves, is a kind, pious woman (in contrast to the Earl, whom Maeb finds dark and secretive). But when word arrives that a plague is sweeping through Europe like a human wildfire, everyone in the Earl’s household is put on edge. It is whispered that victims of this plague are spontaneously engulfed in flames—as if the flames of Hell had suddenly leapt up to claim them. It is also whispered that the Devil himself is to blame.

As the disease spreads into England, so too does civil unrest. King Edmond calls his lords and their armies to return to London, and the Earl obeys, leaving Maeb and his family to fend for themselves. But it turns out that the Earl has been hiding far more than simple state secrets, and that his family, left alone, is at risk of losing not only their lives but also their souls. To her horror, Maeb will learn that, indeed, the Devil himself may have arrived on her doorstep. And worse, what he demands may, in fact, be running through her very veins.