Dragon's Edge is threatened, not just by the on coming swarm of Fireworms, but by Ruffnut and Tuffnut who discover they actually own the island that Dragon's Edge is on.
Fishlegs is excited to find the homeland of the Gronckles. Unfortunately the poor dragons are being terrorized by an unknown dragon. Fishlegs and Meatlug to the rescue.
At Berk, Hiccup finds out someone is attacking and luding ships. They take off to find a Dragon and a rider who is doing this. They find out information and go to the island to find a shocking discovery
Hookfang finds a female Monstrous Nightmare and Snotlout becomes jealous of Hookfangs new relationship. Is this the end of their relationship? Is Snotlout never going to ride again?