Every decade, Aurvandil's Fire arrives to Berk, inviting a ghostly dragon, the Flightmare, to the village. Astrid, with the help of Hiccup and Fishlegs, is determined to defeat this dragon, which seemingly "froze" her uncle with fear, in order to restore her family name. Meanwhile, Ruffnut and Tuffnut create a bunker at the Academy to hide from the Flightmare, allowing everyone in except Snotlout, instead demanding a superfluous amount of unusual tasks, such as bringing rainbow chickens, singing Terrible Terrors, and fish dressed like Stoick to mess around with him.