Crowbone Oathsworn Series, Book 5.

The long awaited return to Robert Low's Oathsworn series Island of Mann, 979AD. A monk lies dying with a sworn secret he must pass onto Crowbone, the true heir to Norway's throne, before he breathes his last. The monk's words will decide the fate of a kingdom. But once the secret is revealed, Crowbone's long-time enemy, Gunnhild, the Witch Mother of Kings, threatens his path to the crown and will stop at nothing to prevent him from attaining his...