Ryker is determined to create a key to the Dragon Eye, so he heads to Glacier Island to find the Snow Wraith that the Dragon Riders are protecting.

When Ruffnut is captured by Dragon Hunters, it's up to Astrid and Tuffnut to defend Dragon's Edge from the invading Dragon Hunter army.

Unaware of the war on Dragon's Edge, Hiccup, Snotlout and Johann discover an island full of dragons that have been wounded by the Dragon Hunters.

When a new tidal class dragon, the Sea Shocker, is found in Edge Cove, the riders must help it escape a group of hungry Scauldrons and reunite it with its migrating pod.

The Skrill returns with a vendetta against Hiccup and Toothless. Hiccup and the Riders must choose a new course of action to stop the vicious dragon.

Hiccup and Astrid race to stop the Dragon Hunters from tracking the Flightmare after Heather spills secrets from Viggo Grimborn.

After Heather and the Flightmare have been captured by Viggo and the Dragon Hunters, Hiccup must hatch a plan to outwit the dangerous new enemy.