Snotlout Jorgenson and his lackeys do the unthinkable and assassinate Stoick the Vast and frame Hiccup for the crime, thereby banishing the heir of Berk from his home. Hiccup is sent to Outcast island and meets Alvin the Treacherous and his hordes, but the Outcasts soon learn that Hiccup has a gift. The ability to tame dragons. Hiccup tames a Night Fury with all the Outcasts watching, and with that, they all vanished without a trace. The boy finds the most ruthless and most bloodthirsty Vikings in the Archipelago for one goal. Conquest. Hiccup's army of Vikings and dragons invade Europe and their goal is to become the most infamous and legendary Vikings in history, and Hiccup himself will prove to the world he's made himself strong and becomes a conquer. Hiccup Horrendous Haddock III will become 'Hiccup the Accused.'

Gobber couldn't convince Stoick to let Hiccup into the ring for dragon training, but situation gets complicated, when Hiccup faces a Monstrous Nightmare during a raid again. Except this time things go very differently thanks to certain black dragon. Over time an unbreakable bond is formed between two lonely souls.