Revoking unruly demons back to Hell is a rough job, but for Theodora, Annabeth, and Harriet, the three half-human women who do it, it pays the bills. Plus, demons are bastards, so they're kind of doing everyone a favor. Then one day an angel comes to them with shocking news: someone has started opening the seven seals of the Apocalypse, triggering the end of the world. He needs their help to identify and stop the culprit before it's too late. Already, Pestilence, the first Horseman of the Apocalypse, has been released, and soon the stars will be falling from the sky and mountains around the world crumbling.

The women are stalked by danger on all sides. Working with the angels means betraying their demon masters, and is it by coincidence or dark design that they keep running into released Horsemen? As they crisscross the city, desperately trying to piece together the clues that could help them save humanity, they discover a secret kept from them since birth holds the key to stopping the Apocalypse...or completing it.