It's been ten years since the dragons moved to the Hidden World, and even though Toothless doesn't live in New Berk anymore, Hiccup continues the holiday traditions he once shared with his best friend. But the Vikings of New Berk were beginning to forget about their friendship with dragons. Hiccup, Astrid, and Gobber know just what to do to keep the dragons in the villagers' hearts. And across the sea, the dragons have a plan of their own...

When Hiccup discovers Toothless isn't the only Night Fury, he must seek "The Hidden World", a secret Dragon Utopia before a hired tyrant named Grimmel finds it first.