It stops for just the smallest fraction of a second, just enough for him to whisper:
“It’s over now. You can rest.”
So they both rest.
Arthur stays in Avalon for as long as Merlin can remember. He’s in peace now, which is all that matters (all that matters to Merlin anyways). He’s also safe there.
And Merlin? Merlin rests as well. No destiny, no duties, no more wars to fight. He’s been set free.
But why does freedom feel so bitter?