Outcasts arrive unexpectedly on the shores of the Edge , disguised as women, which annoys Snotlout. They say that their chief Alvin has been captured by bandits and they need none other than Fishlegs as Thor Bonecrusher to help them rescue him. At passing what the Outcasts said on to Hiccup and the other Riders, Hiccup says it's a bad idea and they should think of another way. But Snotlout invites Fishlegs to his hut to tell him all the marvelous stories of Thor Bonecrusher from last time. Fishlegs agrees to help and asked Snotlout to hypnotize him with a ball and chain. Once under, Snotlout tells him to love Meatlug at Fishleg's request, to snap out of the hypnosis when he claps three times and misinterprets his other request to be more mindful to being "anti-heroic" instead.
Once on Outcast Island, the plan seems to be working at first until it's discovered that "Thor" is actually working on the bandits' side. Snotlout is locked up with Alvin and the remaining Riders now have to find a way to rescue both. "Thor" then unlocks Snotlout only to hold him as a hostage when a battle breaks out. In the battle, Snotlout finally manages to clap three times to bring Fishlegs out of hypnosis, but it didn't seem to work. The remaining Riders regroup back at the Edge while Snotlout is continued to be held as a hostage. "Thor" sends Meatlug to the Edge with a message, and the Riders soon arrive ready to meet the demands. As it turns out, the clapping did work and it was Fishlegs, not "Thor" that came up with the rescue plan after that and caught the bandits off guard, showing he's had Thor's warrior spirit in him all along. Alvin and the Outcasts are set peacefully on their way.
Meanwhile, the bandits report to Krogan that the Ice Tail Pike fish they were demanding for ransom for Alvin was a failure, and Krogan's new partner, Viggo, agrees that tougher measures will be taken in the future to be sure they don't fail again.
Alvin makes his Race to the Edge debut.
Viggo is seen to be officially alive, but with the left side of his face horribly burned.