Arthur woke to Merlin thrashing, convulsing through some sort of night terror. He held Merlin close, and tried to keep him from injuring himself through the spasms, but he was entirely uncertain whether that was even the right thing to do.
He noticed, as the minutes went on, that Merlin had been getting increasingly warmer. With growing terror he realized that Merlin was incredibly hot, burning up as if the dreams themselves were causing some sort of incredible magical fever. Arthur couldn't remember the last time he’d felt so powerless. It was a relief then, if a surprise, when Morgana knocked on their door and entered as soon as Arthur was able to stammer some sort of assent.
Morgana walked in, with a confidence and certainty of action Arthur couldn't remember ever seeing in her before. The room seemed to drop in temperature as she crossed in, and, in moments, she brought a hand to Merlin’s chest and one to his face. Arthur could feel the cold radiating off her. Merlin’s temperature crashed drastically as he woke with a start to the cold shock that rippled through from the point of Morgana's contact, and he breathed in sharp and deep like a man just saved from drowning.
“More like the pyre…” Morgana said, responding to the thought Arthur had never voiced.
Merlin panted as he assessed the situation, assessed the room around him, came back to reality, blue eyes betraying an equal measure of absolute understanding and complete bafflement that Arthur could only hope would be promptly explained