Hiccup decides to run away from Berk without leaving any evidence. But to the village they think he was killed or kidnapped. The only one who knows the truth about his disappearance is Astrid. Hiccup and Toothless decide to go to different islands and convince them otherwise about dragons. When they come across an island it may change the course of their destiny forever. When the island goes up in flames Hiccup loses his only family and vows to avenge them.