When the dragon riders discover a Skrill, a lightning-powered dragon revered by the Berserkers,that happens to be frozen in ice, they scramble to get it off Berk. But when the Skrill is thawed out and unleashed, Hiccup and Toothless are faced with a battle between both the Skrill and Dagur the Deranged's Berserker armada (also hunting the Skrill) which could prove to be more than Hiccup and Toothless can handle. During the battle, the twins witness Alvin in an Outcast ship capturing the Skrill...
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Complete story — includes the ending
When the dragon riders discover a Skrill, a lightning-powered dragon revered by the Berserkers, that happens to be frozen in ice, they scramble to get it off Berk. But when the Skrill is thawed out and unleashed, Hiccup and Toothless are faced with a battle between both the Skrill and Dagur the Deranged's Berserker armada (also hunting the Skrill), which could prove to be more than Hiccup and Toothless can handle. During the battle, the twins witness Alvin in an Outcast ship capturing the Skrill.
Sources and content license
Source and revision history · Adapted from Wikipedia contributors, List of DreamWorks Dragons episodes. HTML formatting and reference markers removed. · Content license