They didn't see what happened before, they only saw him fall.
Merlin. Alone, atop a tower in the castle, back facing towards the courtyard. Wind blowing his hair wildly. Rain soaking his clothes. He stumbled. They saw his hand reach out. To someone else? They couldn't see. It was Arthur who reacted while the rest stood frozen. The future King rushed forward through the crowd, shoving and pushing, eyes on Merlin as he fell. And he caught him just in time. A relieved sigh went up in the crowd, but Merlin didn't stir. He lay like a doll in Arthur's arms.
His fingertips were blue. His lips were covered in blood. Eyes half open, but empty and unseeing.
"Merlin?" Arthur shook the boy, but there was nothing.
The crowd drew in closer. Murmuring, whispering. Gwaine shouted at them to get back. The rain thickened around them. Above, through the clouds, birds began to screech and dive.
"Someone call Gauis!"
Arthur set Merlin on the ground, taking shelter beneath a shop front. Gwaine offered his cloak to cover him as the rain began to roar. They looked for an injury and found nothing. They looked into his eyes, listened to his chest. His body was warm against Arthur's cheek, and quietly, like a mouse at midnight, his heart still beat.
Thank God.
"Where is he?" Gaius' voice was almost lost in the rain.
Gwaine waved, Arthur withdrew. Merlin began to shiver.
Gaius arrived, wet and windblown. He clutched his bag of supplies like a lifeline. Then his eyes fell on Merlin and he frowned. "What's happened to him?"
"He fell." Said Arthur, "But I caught him."
Gaius looked grave.
"We must get him inside."
Inside the castle, the rain still roared. It shook the windows and howled through the corridors. It seeped through gaps and cracks and pattered down into buckets. The air was icy. Gwaine, back in possession of his cloak, stood close to Arthur and wrapped it around the both of them. But still they shivered. In Gaius' chambers, they watched in worry as Merlin lay unmoving.
"You'll have to give me time and space," The physician snapped. He shooed them out. "No point sitting around. And get out of those wet clothes. You'll catch a chill."
In Arthur's chambers, the rain was duller, the air was warmer. He sat alone on his bed, looking into a fire a stranger had lit, palms pressed together and head bowed. At dinner time, Guinevere visited with a meal from the kitchen. She stoked the fire and took away the wet clothes he'd left bundled on the floor. Before she left, she stroked his hair and petted his shoulder. He allowed himself a minute to hold onto her. Sometime around midnight, the rain finally stopped. And the silence that followed was astounding.
Arthur woke to sunlight. He looked outside his window, and it was like the storm had never been. There was music in the courtyard and voices floating up from the markets. Horses clattered by and shop keeps haggled their prices. He saw servants running errands and smelled hot food cooking from the kitchens. And there was the heavy sound of footsteps, booming down the hallway, approaching his room.
"Arthur!" Gwaine entered without knocking, but Arthur allowed it. Just this once. He braced himself.
"I've come from Gaius. He said he'll live."