The special opens on the Haddock family in their living room and Hiccup preparing to light the fire. Zephyr and Nuffink run off to feed the dragons while Astrid says she's going to go make some Yaknog and steps off screen. Unable to

Hiccup and Toothless reunite to remind both their kinds of the inseparable bond between vikings and dragons.

A hapless young Viking who aspires to hunt dragons becomes the unlikely friend of a young dragon himself, and learns there may be more to the creatures than he assumed.

When Hiccup and Toothless discover an ice cave that is home to hundreds of new wild dragons and the mysterious Dragon Rider, the two friends find themselves at the center of a battle to protect the peace.

While a zombie virus breaks out in South Korea, passengers struggle to survive on the train from Seoul to Busan.

When Hiccup discovers Toothless isn't the only Night Fury, he must seek "The Hidden World", a secret Dragon Utopia before a hired tyrant named Grimmel finds it first.

Tony Towers is a local celebrity, a successful nightclub manager and he is engaged to a younger woman, Sue. Things get a little strange when he embarks upon the 3:17 to Nottingham for a Christmas family reunion.

In Barcelona, secret agent Antoine Donadieu thwarts the plans of a Nazi scientist.