“The corridor dissolved, and the scene took a little longer to reform: Harry seemed to fly through shifting shapes and colors until his surroundings solidified again and he stood on a hilltop, forlorn and cold in the darkness, the wind whistling through the branches of a few leafless trees. The adult Snape was panting, turning on the spot, his wand gripped tightly in his hand, waiting for something or for someone… His fear infected Harry too, even though he knew that he could not be harmed, and he looked over his shoulder, wondering what it was that Snape was waiting for —
Then a blinding, jagged jet of white light flew through the air. Harry thought of lightning, but Snape had dropped to his knees and his wand had flown out of his hand.
“Don’t kill me!”
“That was not my intention.”
Any sound of Dumbledore Apparating had been drowned by the sound of the wind in the branches. He stood before Snape with his robes whipping around him, and his face was illuminated from below in the light cast by his wand.
“Well, Severus? What message does Lord Voldemort have for me?”
“No — no message — I’m here on my own account!”
Snape was wringing his hands. He looked a little mad, with his straggling black hair flying around him.
“I — I come with a warning — no, a request — please —”
Dumbledore flicked his wand. Though leaves and branches still flew through the night air around them, silence fell on the spot where he and Snape faced each other.
“What request could a Death Eater make of me?”
“The — the prophecy… the prediction… Trelawney…”
“Ah, yes,” said Dumbledore. “How much did you relay to Lord Voldemort?”
“Everything — everything I heard!” said Snape. “That is why — it is for that reason — he thinks it means Lily Evans!”
“The prophecy did not refer to a woman,” said Dumbledore. “It spoke of a boy born at the end of July —”
“You know what I mean! He thinks it means her son, he is going to hunt her down — kill them all —”
“If she means so much to you,” said Dumbledore, “surely Lord Voldemort will spare her? Could you not ask for mercy for the mother, in exchange for the son?”
“I have — I have asked him —”
“You disgust me,” said Dumbledore, and Harry had never heard so much contempt in his voice. Snape seemed to shrink a little, “You do not care, then, about the deaths of her husband and child? They can die, as long as you have what you want?”
Snape said nothing, but merely looked up at Dumbledore.
“Hide them all, then,” he croaked. “Keep her — them — safe. Please.”
“And what will you give me in return, Severus?”
“In — in return?” Snape gaped at Dumbledore, and Harry expected him to protest, but after a long moment he said, “Anything.”
―
J.K. Rowling,
Harry Potter and the Deathly Hallows
