The movie is a sequel to 2010's 'How to Train Your Dragon' and 2014's 'How to Train Your Dragon 2'. It is the third and final installment in the How to Train Your Dragon trilogy.
After becoming the chief of Berk, Hiccup has fulfilled his dream of creating a peaceful dragon utopia, while the sudden discovery of a wild, elusive mate lures Toothless away. When danger threatens their village and tests Hiccup's reign as chief, Hiccup and Toothless are forced to leave the only home they know. As they travel to a hidden world thought to only exist in myth, both dragon and rider will fight together to the very end to protect everything they love in order to take down a dangerous enemy.