The question had been in the back of Arthur's minds since that moment when Merlin came into his room. It was just after he had awoken from the questing beast incident and was highly amused to see Merlin slam open his door and close it shut with a snap. He would've reprimand him if it was not for that look on his usually happy and amused face. Where there should've been a smug smile and gleaming eyes that would be telling him he told him so instead there was a frown and unquestionable sadness. All Arthur could do was listen as Merlin talked; and long after he was gone and long after he had come back Arthur would go back the words that echoed in his head.
"I am glad to be your servant till the day i die."
Months latter, which led to years, he forgot all about the conversation until one day in all came back in a blur.
An attack on Camelot which no one expected happened at dawn on a dismal day. The knights of Camelot stood on the battlements and shot arrows far across the grounds sinking into their targets while watching desperately as their brethren attacked on foot. They were so far away yet to them they seemed so close, to hear the snapping of bones and smell the metallic red blood that littered the filed. The king stood by them while the blood left his face; all hope of winning was loss.
"My lord, look!" shouted Gwaine in surprise as he drew the bow up on his shoulders and leaned over for a better look. The others followed his lead and gasped as Merlin, the high warlock of Albion, stood in the core of it all.
He raised a fist in to the air and yelled a string of magnificent and terrifying words that Arthur knew was a spell. He had sworn that his heart stopped beating as his friend cast a gold light into the air and he turned gold. All had to shield their eyes as the battleground was covered in light.
When it disappeared none where left besides Merlin who dropped to the ground.