Vikings are big fans of outdoor sports—like swimming competitions in icy water.
And so Hiccup Bloodthirsty Carp III, with his friends and pet dragons, is freezing on the shore before the Traditional Viking Swim and still doesn’t know that the swim will last—o-o-o-very, very long, and that the outcome of the contest will determine the fate of all the Hairy Hooligans and Boar-Babes.