When the king arrived in Camelot, he spoke to no one until he entered Gaius's chambers. Yet he saw that news of his approach had preceded him, for the court physician's face was a still mask. Arthur could imagine what the old man was thinking: that perhaps the guards were mistaken, or perhaps Merlin had been sent on some errand and elected to go on foot. Just because the king returned alone with a riderless horse didn't mean...couldn't mean...
Arthur's sympathy was tempered by a vague suspicion. Had Gaius known? Was he a willing accomplice in Merlin's crimes? Or had he been fooled like the rest of them? Arthur decided that he didn't want to know. He'd already lost one friend, and Gaius's grief would be punishment enough for whatever part he may have played. He handed over the scroll he'd retrieved from the tomb, and watched the carefully schooled expression slip as the silence between them lengthened.
"Sire...?"
"I'm sorry, Gaius. I'm truly..." Arthur swallowed.
"He can't be gone." The words were a stricken whisper, all the more heartbreaking for their discordance. Arthur had thought nothing could shake the indefatigable physician. He faced death with calm professionalism every day, kept calm when the entire kingdom was at risk. To see his spirit crushed was as disheartening as watching the city itself fall.
Arthur opened his mouth to disclose Merlin's treachery, but the desolation in Gaius's slumped figure changed his mind. "We would not have the scroll were it not for him. He saved the kingdom." Those last words echoed strangely in Arthur's mind, and he had to swallow hard as he realized the truth of them.
"Of course, I'll...I will get started right away."
The king nodded and turned, unable to watch Gaius's dazed, wooden movements. The man would grieve quietly, and continue serving his king, but Arthur knew he would never be the same. A piece of him had left with his boy, and would not return until Merlin did.