Fishlegs thinks he’s caught a cold—but Old Wrinkly reveals the terrifying truth: he’s been stung by a Venomous Vorpent, and he’s dying of VORPENTITIS. The only cure? The legendary and fearsome Vegetable-that-No-one-Dares-Name… the POTATO. To save his best friend, Hiccup must battle Norbert the Nutjob and the monstrous Sea Dragon known as the DOOMFANG. Can one small Viking outwit death, defeat a dragon, and uncover the secret to breaking the curse? (Book 4)