"I will become the monster they expect. I will be the nightmare that nightmares dread." After Procyon's mother sells him to a monster in a castle, he agrees to serve it to protect the only person left that he cares for. That is, until he can twist his knife into its stomach. But his plan to kill the monster is ruined by a secret so dark and twisted that it will change the course of his life forever. Meanwhile, Lavine's sister is kidnapped by the most brutal and merciless kind of monsters. But the closer she gets to uncovering her sister's whereabouts, the more she understands the horrifying truth. She'll need to use the darkest, most corrupting part of her soul magic to save her. Too bad the price just might be her own soul. Heir of Thorns is the gripping prequel to the epic YA series, The Crest of Blackthorn. It can be read before or after any title in the series, though the events take place before the first book, Wither Thorn.