(For a drabble tree. The section in bold is the inherited text.)
The dark mist retreated to reveal McKay lying unconscious on the ground. Sheppard was down the stairs and kneeling at his side before the others had moved.
He'd meant to check McKay's pulse, but instead just stroked his arm. Sheppard knew what it felt like to search for signs of a life that was gone, and the thought of finding no heartbeat in the man lying before him filled him with a sudden, sharp dread.
"He's breathing," Weir pronounced, and Sheppard's own breath returned. He gave McKay's arm a squeeze and drew his hand back, hoping no one had noticed.