Grubbs Grady, his magical mentor Beranabus, and their ally Kernel-all featured in previous volumes—battle their way through the alternate worlds of demons and other creepy creatures. They kill all the demons they can while hoping to learn more about the monstrous power that propels the demon forces to slaughter humanity. The teenager Grubbs, as readers know from earlier installments, carries a family curse that could turn him into a werewolf, and it takes all of his magical talents to keep that curse at bay. If that happens, he will be hunted down and killed by a group called the Lambs. When fellow demon-fighters Meera and Shark appear through a window from the human world, they ask for help. Grubbs's beloved Uncle Dervish has been attacked by werewolves and is near death, and the Lambs may have allied with Lord Loss, the series' main villain. Grubbs and the other demon fighters learn that things are worse than they thought (in the "Demonata" books, they always are)—the Lambs are now breeding werewolves at Wolf Island, a remote lab and fortress. Like all of the books in this series, Wolf Island is not for the squeamish; blood and death are gruesome constants and triumphs are only temporary.