After days of searching the mountains for a pass off the plateau, Roxton and Marguerite are camped for the night when they are taken by surprise by Norse warriors. Roxton is run through with a sword by the leader, Ursula. As he sinks to his knees, Marguerite is hauled off by the raiders. Near death, Roxton is visited by a mystical young boy named Osric, who offers a deal. Osric will restore Roxton's life so he can save Marguerite. However, there is a catch. Roxton agrees to the deal and Marguerite is saved. It turns out that Osric is the soul of evil who has been imprisoned on the Lost World. He reappears and gleefully informs Roxton that he must murder Bergen, an old man with a long-standing hold over the boys' manipulative intentions. Roxton refuses to kill the old man, but Osric has many deadly ways to get what he wants. Meanwhile, Malone and Veronica must defend their Treehouse from a band of cutthroats who will stop at nothing to take it from them.