In the next installment of the movie which has been reported by CP Entertainment to be released on June 29, 2018, Toothless and Hiccup will be going on separate ways due to a conflict that will arise between humans and dragons.
It was stated in the report that Drago, the villain who had been defeated by Toothless and Hiccup in the last movie, will be finding a way to convince Toothless to turn its back from Hiccup. According to DeBlois, the director of the movie, fans will be able to witness how Toothless will struggle to become an independent dragon and how Drago's more evil character will manifest in the story.
"We are gonna take the story to where the books begin, which is Hiccup as an adult reflecting back on a time where there were dragons, suggesting that the dragons will in some way go away. Why and could they come back and the mystery of what all that is will be saved for the actual story," said Deblois.
Parent Herald notes that the movie will also focus on Hiccup becoming an adult and how Toothless and Hiccup will battle with each other to stand for what's best for their respective races.
As for the actual status of the movie, Collider in its report mentioned that during an interview with DeBlois, he is now currently working on the 60th page of the screenplay and mentioned about how he went through a rigorous process before finally working on the script:
"There were a few months of pitching outlines and making sure that everybody was content with where it was headed, and now I'm deep into the script. I'm about halfway through. I was literally working on it this afternoon before coming here. I have to hand it off pretty soon."
Though showing is still a few years from now, fans are surely anticipating the film that will complete the trilogy.