Merlin didn't know what he should do with Arthur anymore; he had become distanced after their journey to the Fisher Kings lands. Merlin were planning on going to Ealdor to visit his mother.
So Merlin left a letter to Arthur in Gaius' chambers, thinking that Arthur would like to see him gone after his little, lets save Arthur with Gwaine. Well, at least for a couple of days.
But Arthur, having these weird and 'wrong' thoughts and erotic dreams, all about his annoying manservant. He wanted to hold him and protect him from the dangerous world outside the castle walls.
Arthur went to Gaius' chambers, because his Merlin- wait what his Merlin? Anyway he went to Gaius' chambers to find Merlin, because he didn't show up that morning. But Arthur couldn't think all straight, because Merlin were always awake to the chance of annoying the Prince of Camelot. But sadly Arthur only found a letter addressed to him from Merlin. But where were Merlin?
Arthur put the letter in his pocket and left, because he didn't find Gaius. Arthur then left and went to his chambers and opened the letter.
Arthur…
When you read this I'll already be outside the gates of Camelot. But I am on my way to Ealdor to visit my mother, but I'll be cack in a weeks time, so don't worry about me.(Not that I think you would.) I'll hope you'll be 'big enough' to take care of yourself in a week. If not get a servant for the week, or you could come to Ealdor with me? Plus you'll have to visit the border some time.
So see you soon.
- Merlin.
So Arthur packed at backpack and set out to follow Merlin to Ealdor…
