Troll Hunter is set in a world sparsely populated by humans and trolls. The story follows Gabril Cullen, a human scout with the ability to track trolls by scent. Trolls have raided human territories for generations, killing or capturing humans for slaves. Cullen is drawn into a trap and kidnapped by a party of trolls. The trolls need a scout with the scentgift to track down trolls captured by the demonic creature Azuk and to aid in defeating the demon. To accomplish his task, Cullen must overcome a lifetime hatred of the troll race.

Chapters alternate between Cullen’s POV, his daughter Isabo, and the troll Gheen.