In the full plot of How to Train Your Dragon: The Hidden World (2019), Hiccup leads Berk away from the hunter Grimmel, finds the dragon haven, and says goodbye to Toothless, with an epilogue a decade later. Hiccup wants to lead the village to the Hidden World, but the Light Fury, who was handed to Grimmel as bait, meets Toothless in the woods, where the two are plainly drawn to one another. She runs when she senses the humans nearby.
Grimmel then confronts Hiccup and demands Toothless. His Deathgrippers wreck much of Berk, so Hiccup leads the villagers and their dragons away by sea. They settle on an island they name New Berk, and Toothless leaves to join the Light Fury. Grimmel lays a trap for the group, though most of them escape it.
Hiccup and Astrid find the Hidden World, where Toothless is now the alpha and the Light Fury is his mate. Seeing it, Hiccup realizes that humans do not belong there. Grimmel has followed them, though, and he captures both dragons, then uses Toothless to take control of the dragons of Berk.
Hiccup and the riders strike back using wingsuits and free Toothless, but Grimmel drugs the Light Fury and flies off with her. In the chase that follows, Hiccup and Toothless beat the Deathgrippers, but Toothless is tranquilized and falls. The Light Fury rescues him, and Grimmel falls to his death.
Hiccup and Toothless accept that dragons are not safe among humans. Hiccup says goodbye, and the Berkians release their dragons. A decade later, Hiccup and Astrid, now married with children, visit Toothless and the Light Fury, who have three young hybrid dragons.