After an attack on Berk, Astrid trains a crew of backup Dragon Riders to battle back—but no one can guess how soon the next strike will hit.

A new enemy named Ryker Grimborn captures Stormfly, sending Hiccup, Toothless and the team off to rescue her before it's too late.

As Hiccup and Snotlout race to rescue the others from the Dragon Hunters, they don't realize that someone close to them is working with the enemy.

After a strange creature bites Tuffnut, he believes he'll turn into a legendary Lycanwing dragon when the moon is full. Can his friends save him?

Snotlout and Astrid must deliver a special battle axe to a family wedding, but when an Armorwing dragon derails their plan they have to work together.

After Hiccup and Toothless heroically save Barf and Belch, the grateful Zippleback tries to repay its life debt by abandoning riders Ruff and Tuff.

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.

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.