Sudden lightning storms are endangering the residents of Berk and it is believed Thor is angry at the island. Mildew leads the superstitious villagers into blaming Toothless, "the unholy offspring of lightning and death itself", for the lightning, leaving Hiccup to find the true answers for Thor's sudden destructive anger.
Elenco: Jay Baruchel , America Ferrera , Christopher Mintz-Plasse , T.J. Miller , Zack Pearlman .