Hiccup Horrendous Haddock III's best friend, Fishlegs, has been stung by the deadly Venomous Vorpent! The only cure is the Vegetable-That-No-One-Dares-Name. But where will Hiccup find such a thing? He'll have to dodge the terrible Sharkworms, battle Doomfangs, and outwit crazy Hooligans if he's going to be a Hero (again).