Hiccup, Toothless and the dragon riders journey to Glacier Island in search of the Snow Wraith, a fearsome new dragon that holds the key to the Dragon Eye's mysteries.
The dragon riders discover a lush island that turns out to be the home of the Deathsong, a massive, never-before-seen dragon that threatens to trap them forever.
Thinking he's allergic to his best friend Meatlug, Fishlegs gets hypnotized – and wakes up transformed into an invincible warrior known as Thor Bonecrusher.
A familiar face joins ranks with the dragon riders, but it's not an easy alliance, especially when Hiccup uncovers a shocking secret about the new member's true identity.
