A massive conflict erupts on Outcast Island involving the Riders, Alvin's forces, and the Berserkers. The Screaming Death eventually reunites with its mother and leaves the archipelago in peace. Key Outcomes & Trivia

Hiccup decides to trust Alvin the Treacherous , who has returned seeking to make amends. Together, they infiltrate Outcast Island via a secret underwater tunnel system.

This is officially the only episode in the series that features a narration by Hiccup at the very end.

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