John's head breaks the surface of the water.
He gasps for air and splutters out, "Sherlock w-"
Sherlock. Where's Sherlock? He should have come up by now.
Something brushes his hand. He looks at the dark mass. Oh god no.
John grabs Sherlock's limp form around his middle and hauls his face up out of the water. Then, with a burst of sudden strength, he swims through the murky water until he reaches the edge of the lake, still supporting Sherlock all the while.
John drags Sherlock's body up onto the muddy ground. He turns the unresponsive detective over, all of his doctor instincts kicking in. No heartbeat. Oh god. God no.
He begins pumping his hands on Sherlock's chest, checking every now and then to see if he's getting a reaction. Nothing.
John begins to panic.
"You're not dying on me."
He doesn't know who he's talking to. Sherlock can't hear him. They're alone at the bloody lake that Sherlock insisted would make a good escape by jumping into it.
John places two fingers on Sherlock's neck. Stillness. He crashes his hands down onto Sherlock's chest, making Sherock's body twitch. Still nothing.
John tilts Sherlock's head toward him. He lowers his head and clamps his mouth firmly onto Sherlock's. He pinches Sherlock's nose and begins breathing for Sherlock. He checks for life again, but there's nothing, not even a breath.