Quick recap
A ball of fire rolls down the mountain: the Exterminators, evil fire dragons. Hiccup and Gobber are saved by Humungously Hotshot, one of the greatest heroes on the planet, and Stoick hires him as his son's bodyguard. One night Hiccup wakes to find the hero standing by his bed, swords in hand, arguing with himself about whether to kill him. To understand why, Hiccup hears a story of love, of a ruby and of a fire stone that has to be carried to a volcano. That stone could save a whole island.
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