Wolf Island — Darren Shan

As the mysterious Shadow builds an army of demons, Grubbs Grady and his team search desperately for answers. But when they follow up a new lead, it takes them to an old, unexpected foe - the Lambs.

"We spot the werewolves as we skim the treetops. Mutated, vicious, hairy monstrosities, all fangs, claws and muscles. The beast within me tries to force its way to the surface, howling silently at its warped brethren. I've never rid myself of the wolf..."