When Jim's older sister, Monica Lake, comes back from college, she is surprised to hear from her mother that Jim hasn't been himself lately. That he's been getting into trouble. When she discovers why, she receives the adventure of a lifetime.
Everyone says that the amulet doesn't make mistakes so Jim was always meant to be the TrollHunter, it was his destiny. So why did it choose Tobias Domzalski at then end of the movie? The answer could be that it knows what Jim did and is simply working as part of his plan to 'make right'. With Toby as TrollHunter, Jim...