The Riders learn of Ryker's attack on the Edge and attempt to stop the Shellfire and keep the Dragon Eye from being reclaimed by the Hunters.

While trying to stabilize the volcano that threatens to destroy Dragon's Edge, the Riders discover troubling evidence of new Hunter activity.

As the Riders investigate why traders are disappearing from the Northern Markets, Hiccup and Snotlout fall victim to a treasure-hoarding dragon.

The Outcast leader, Alvin, is kidnapped and held for ransom by bandits. They call on the Dragon Riders to request the assistance of Thor Bonecrusher.

After the Edge is ambushed by a group of Singetails, the Riders quickly take flight to ward them off, but are shocked when they get a closer look.

The Riders flee to Berk, where Stoick's plan for defeating the Flyers, which will require a painful sacrifice, spurs Hiccup to seek an alternative.

Stoick and Hiccup are led on a wild goose chase in search of willow bark for medicine, leaving Berk vulnerable to an enemy attack.

During a trip to Wingmaiden Island to find a Dragon Eye lens, Snotlout challenges Hiccup's leadership. On another island, an unlikely romance blooms.

Upset after learning his ancestors were Hunters who killed off Dramillions, Fishlegs sets out to see if he can find any of the dragon species left.

An announcement leads Astrid to question her relationship with Hiccup. The Riders discover an Armorwing that has a Dragon Eye lens welded to its body.

When the Flyers try to kill him because he's no longer useful, Viggo forces Hiccup to help him get revenge by stealing their Dragon Eye and lenses.

After learning Krogan is using a Deathsong to lure and subdue Singetails for his growing army of Flyers, the Riders set out to rescue the dragon.

With the fifth lens in place, the Dragon Eye 2 unveils the apparent King of Dragons, and Fishlegs immediately knows what it is and where to find it.