"Hiccup is in hiding in the Murderous Mountains with the Company of the Dragonmark, but he is determined to become King of the Wilderwest by defeating the witch's Vampire Spydragons and steal back the King's Things from Alvin the Treacherous"--
Someone has stolen the fire stone, so eggs of exterminator dragons are hatching. Hiccup must return the fire stone to the volcano to save the Tribes from being wiped out.
Follows the further adventures and misadventures of Hiccup Horrendous Haddock the Third as his Viking training continues and his father leads a stranger and the Hairy Hooligans to the Isle of Skullions in search of a pirate's treasure.