When Nathalie turns twenty, she knows that social rules dictate that it is time for her to marry. However, before she takes this life-changing step, she goes onto one last trip with her adventurous older brother. This leads them to D'Arcy Castle, a centuries-old estate owned by a master who is supposedly a monster. When their visit threatens to turn into a bloodbath, Nathalie makes the decision to stay at D'Arcy Castle to save her brother. Trapped and isolated, the very thing she was trying to put off, Nathalie soon finds out that the woods behind the castle aren't just woods - and that the monster of the castle is more than he seems.
In the epic conclusion to the Devil's Deal series, Freya has one final chance to discover the full potential of her own power, and to use it to restore balance in the universe - once and for all. After the destruction caused by Roisin, Ferya and Torix come to terms with their losses and mistakes... And prepare for a final battle that will change everything.