Oath Breaker is the fifth book in the Chronicles of Ancient Darkness series written by Michelle Paver and illustrated by Geoff Taylor.

Oath Breaker is preceded by Wolf Brother (2004), Spirit Walker (2005), Soul Eater (2006), and Outcast (2007), and followed by Ghost Hunter (2009), Viper's Daughter (2020), Skin Taker (2021), and Wolfbane (2022).

Torak eventually finds his way to Thiazzi, while Renn defies the Deep Forest clan who captures her by showing them her bond with Wolf and the ravens, Rip and Rek, an ability which they do not believe a woman could have.

Torak grimly starts preparing for an upcoming fight against Eostra, the Eagle Owl Mage, the last and greatest Soul Eater.

[1] Similarly, School Library Journal's Genevieve Gallagher highlighted how "Paver blends her knowledge of animals and the ancient European landscape with magic and legend".