Venezuelan president Nicolas Maduro makes moves toward turning the country from a democracy into a dictatorship, creating a growing opposition to his rule.
Jestro and the Cloud of Monstrox builds a new stone army from giant building blocks to crush Knighton. The Nexo Knights try to convince Rockowski, a demolition expert, to help them.
In 1997, a son must teach his mother how to use the Internet over the phone after leaving behind an important document on his laptop.
Bob mistakes a mud-covered pig for Rolly and accidentally leaves him behind on a farm.
Elena and her friends get stranded on a sailboat and are rescued by a mysterious ship.
An unlikely ally helps Hiccup uncover Singetail behaviors that can be exploited to conquer the Flyers. An overconfident Krogan makes a strategy error.
When Ruffnut refuses to become Throk's bride because it would mean leaving her twin, Tuffnut fakes his own death to give her the freedom to marry.
After Stormfly tangles with two poisonous Slitherwings while defending Garff, Astrid must risk her own life to get an ingredient to make an antidote.
When Heather goes to meet a man claiming to have seen Oswald, she walks into a trap that forces the Dragon Riders to pay a dear and unexpected price.
A sketch in an old diary leads Hiccup and Fishlegs back to Vanaheim, where they help Dagur search for his long-missing father, Oswald the Agreeable.
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.
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.
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.
Disobeying Hiccup, the twins follow a retiring Eruptodon to its final resting place, Vanaheim, and learn why no human has ever gone there before.
When Snotlout is rescued from a storm by a tribe of winged women, he thinks he's gone to Valhalla -- until he learns he's going to be their dinner.
While trying to stabilize the volcano that threatens to destroy Dragon's Edge, the Riders discover troubling evidence of new Hunter activity.