When Jade Summers's mother dies, she leaves behind a legacy as a magnificently talented witch - and a mysterious box that she implores Jade to guard with her life. But when her uncle Fred shows up to snatch the box from her, the dark secret of its contents is revealed: inside is Arcadius, an unstoppable demon who had been kept imprisoned by Jade's family ever since the days of the Salem witch trials. Now that he's free, he's bent on avenging his captivity on Jade - while leaving behind as much mayhem as he can wreak.