It was this last fall that had really taken it out of Toothless. They'd crashed plenty of times in all the years they'd flown together, but this had been by far the worst. Toothless wasn't going to fly again.
No one had any clue what was wrong with Toothless: not Gobber, not Astrid, and not Hiccup. Everyone knew, though, that Toothless was not long for this world.
Hiccup had cried as he tried to make Toothless more comfortable. He removed all the flying equipment that he had perfected over the years to fly better with Toothless. Everything, that is, except the barest bones: the saddle, the stirrups, and the prosthetic tail. Toothless, despite his weakened state, had fought against Hiccup when he tried to remove those. In the end, Hiccup left them on. They seemed to comfort Toothless.
Gobber, Stoick and Astrid took turns watching after Hiccup, who never left the chair by Toothless' side. It was during one of the rare moments that the two of them were alone, though, that Hiccup realized he was going to have to say goodbye.
It was a few moments later that Hiccup noticed that Toothless had stopped breathing. He got up and knelt down beside Toothless' face before gently nudging him.
"Hey, bud?"
Toothless didn't react.
"Toothless, bud, are you okay? Toothless? Toothless!"
Hiccup's cries became more panicky as he realized that he had lost Toothless. He swallowed back a sob before placing a hand on the front of Toothless' nose, just like he did many years ago the night in the cove.
Hiccup struggled to get the words out, but he wanted to say one last thing to the dragon who had been his best friend for such a long time.
"Th-thanks, bud," he choked out, "for…for everything. You were amazing."
Hiccup broke down sobbing, one hand holding his face, the other one still resting on Toothless. Astrid found him there a few minutes later. She went and got Stoick, and the two of them stood there, watching Hiccup as he mourned the loss of his best friend.