Luna, a Night Fury driven by vengeance, seeks out Toothless to join her in overthrowing the Bewilderbeast-a tyrant enslaving dragons and amassing an army to destroy Berk and kill Toothless. As the battle looms, Toothless uncovers the shocking truth that he isn't the last of his kind. Together, they must confront the false king, restore freedom to dragonkind, and protect the future of Berk in a fight for survival and redemption.

This takes place after Toothless made himself known during Hiccup's final Dragon Training lesson, exiling himself after an argument with Stoick, but being joined by the rest of the trainers. What adventures await them? New love? Long lost relatives? Tough foes? All we know is, they have dragons.