Harry put off the moment of total submersion from second to second, gasping and shaking, until he told himself that it must be done, gathered all his courage, and dived.
The cold was agony: It attacked him like fire. His brain itself seemed to have frozen as he pushed through the dark water to the bottom and reached out, groping for the sword. His fingers closed around the hilt; he pulled it upward.
Then something closed tight around his neck. He thought of water weeds, though nothing had brushed him as he dived, and raised his hand to free himself. It was not weed: The chain of the Horcrux had tightened and was slowly constricting his windpipe.
Harry kicked out wildly, trying to push himself back to the surface, but merely propelled himself into the rocky side of the pool. Thrashing, suffocating, he scrabbled at the strangling chain, his frozen fingers unable to loosen it, and now little lights were popping inside his head, and he was going to drown, there was nothing left, nothing he could do, and the arms that closed around his chest were surely Death’s…
Choking and retching, soaking and colder than he had ever been in his life, he came to facedown in the snow. Somewhere, close by, another person was panting and coughing and staggering around, as she had come when the snake attacked…Yet it did not sound like her, not with those deep coughs, no judging by the weight of the footsteps…
Harry had no strength to lift his head and see his savior’s identity. All he could do was raise a shaking hand to his throat and feel the place where the locket had cut tightly into his flesh. It was gone. Someone had cut him free. Then a panting voice spoke from over his head.
“Are—you—mental?”
Nothing but the shock of hearing that voice could have given Harry the strength to get up. Shivering violently, he staggered to his feet. There before him stood Ron, fully dressed but drenched to the skin, his hair plastered to his face, the sword of Gryffindor in one hand and the Horcrux dangling from its broken chain in the other.
“Why the hell,” panted Ron, holding up the Horcrux, which swung backward and forward on its shortened chain in some parody of hypnosis, “didn’t you take the thing off before you dived?”
Harry could not answer. The silver doe was nothing, nothing compared with Ron’s reappearance; he could not believe it. Shuddering with cold, he caught up the pile of clothes still lying at the water’s edge and began to pull them on. As he dragged sweater after sweater over his head, Harry stared at Ron, half expecting him to have disappeared every time he lost sight of him, and yet he had to be real: He had just dived into the pool, he had saved Harry’s life.
“It was y-you?” Harry said at last, his teeth chattering, his voice weaker than usual due to his near-strangulation.
“Well, yeah,” said Ron, looking slightly confused.
“Y-you cast that doe?”
“What? No, of course not! I thought it was you doing it!”
“My Patronus is a stag.”
“Oh yeah. I thought it looked different. No antlers.”