Reluctant hero Hiccup Horrendous Haddock III must rescue his best friend, Fishlegs, from the deadly disease Vorpentitis. The only cure is rare and almost impossible to find...a potato. 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.