Revoking unruly demons back to Hell is a rough job, but for Theodora, Annabeth, and Harriet, the three half-human women who do it on behalf of the Daemonium, it pays the bills. Plus, demons are jerks, so they're kind of doing everyone a favor. But when an angel appears with the shocking news that someone has started opening the seven seals of the Apocalypse, setting in motion the end of the world, they find themselves facing a seemingly impossible problem: how do you find and stop someone who scares even angels...and you work for demons? It's a dangerous mission with terrible odds. Already, Pestilence-the first Horseman of the Apocalypse-has been released, and the longer it takes them to find the culprit, the more Horsemen will be freed. As the women crisscross the city, desperately trying to piece together the clues that could help them save humanity, they discover that a secret kept from them since birth holds the key to stopping the Apocalypse...or completing it.