Knowledge is power... Several months after discovering the real reason behind his mother's confinement to a psychiatric hospital and her eventual death, Otis Boone is at a crossroads. With the Vatican's experts still unable to translate her journals, he goes on a desperate search for someone who can help him decipher the hidden code in her writings. After hearing a rumor about a mysterious collector, Otis persuades Artemus Steele and his group of unearthly housemates to accompany him to Salem. But the arcane bookstore owner they meet is even more mystifying than they expected. Sebastian Lancaster has spent the last two centuries trying to forget the awful night a monster invaded his home and slaughtered his family. When Artemus and his allies break into his bookstore and inadvertently bring a horde of demons with them, Sebastian finds himself thrust into an adventure he never wanted. Fate comes calling when he crosses path with an enigmatic Theology professor and events unfold that neither he nor Artemus could have anticipated. As they race against time to save one of their own, Artemus and Sebastian must put aside their differences and work together to track down a demon hideout in England. But Sebastian is hiding a secret. One that has the potential to bring Hell to Earth.