With the Eruptodon kidnapped by Viggo and his hunters, it is up to Hiccup and the Dragon Riders to save it and prevent war between Berk and the Defenders of the Wing.
- Bruiser with a Soft Center: While destructive under desperation, the Great Protector is actually very docile.
- Convection Schmonvection: The lava is bizarrely inconsistent in its lethality. Some felled trees stop it with no problem, but a rock dropped on the trees melts instantly. More rocks are similarly ineffective, until Barf and Belch get the idea to drop the Great Protector monument in its path.
- Gondor Calls for Aid: Meatlug calls all the wild Gronckles in the area to feed the Eruptodon with their lava attack.
- Rescue Romance: Mala picks Snotlout as a potential suitor after he indirectly saves her from an arrow, claiming that her future king would be foretold to do the very same. Downplayed, since she seems to think so pragmatically, neither offended or disappointed when he avoids the trials.
- Timed Mission: Due to the Eruptodon's eating habits, the riders have to return it to its volcano before it starves to death. If they fail, not only will it starve to death within a day, but the lava flow will destroy the Defender's village and Berk will have a new enemy on their hands.
- Villainous Demotivator: Subverted, as Mala is more of an Anti-Hero. She makes that claim that if they fail in their mission or if Hiccup and the riders try anything suspicious, she will kill them herself.