Oath Breaker by Michelle Paver

It’s been a few months since Torak was turned outcast and hunted, then his status as outcast overturned. But even back among his friends and family, Torak still feels the effects of having been outcast from the clans. Along with his cousin Bale, Torak journeys to an isolated part of the Seal clan’s island to search for clues about a fragment of the Fire Opal, the powerful stone that the Soul Eaters want so desperately. One night however the two young men argue, and Torak leaves. The next morning Torak returns to find his cousin dead.

Torak knows that Bale was murdered, as an expert tracker he can read the signs on his cousin’s body, and he swears to hunt down the killer. As Torak begins to track the killer’s movements he realizes that who knows who it is, he’s looking for Thiazzi the Oak Mage, one of the Soul Eaters. Together with Renn and Fin-Kedinn, they track the Oak Mage to the Deep Forest. A foreboding place as the best of times, the Deep Forest clans have been on edge since the plague, and outsiders from the open forest clans are not welcome.

When Fin-Kedinn is seriously injured in a trap laid by Thiazzi, tracking him through dangerous territory falls to the two young people, who have had little interaction with the reclusive clans of the Deep Forest. As the Oak Mage’s traps become more and more deadly Torak must decide if his revenge for the dead means more than the safety of the living.

A very satisfying fifth installment of the Chronicles of Ancient Darkness series, Oath Breaker delivers all the action and heartrending twists that Paver has done so well since in the first book as Torak learns more about both his talents and the choices his parents made even before his birth and how those choices they led Torak to where he is now.