Snape looked into Dumbledore's eyes and knew right away he couldn't do it. Dumbledore was asking him to do a task that would guarantee Voldemort believing Snape was on his side, but how could he betray the one man who had ever believed everything he had said. It was Dumbledore who guaranteed Snape's safety when he spilled the plan about Voldemort going after Lily and James Potter to kill their son, Harry. Snape did it for the woman he loved, but now even she was gone. Snape had nothing except Dumbledore, his job as Potions master, and then the students. He didn't really like the students, but they were a part of his life; they were a part of his life whether he wanted it or not.
The worst part was Harry Potter. Year after year he had walked into Snape's classroom looking like his father who had tormented him in his years at Hogwarts. Harry looked exactly like his father, except for his eyes. Harry had his mother's eyes; Harry's eyes tormented Snape every single day he saw the teenager walking with his friends, Hermione Granger and Ron Weasley. In a way, all three combined made Lily Potter's image, Harry with her eyes, Ron with her hair color, and Hermione Granger with Lily being muggle born and the top of her class. How could Snape do anything but hate the trio that tormented him endlessly.
"Severus," Dumbledore said while leaning over his pensive.
"I can't," was all Snape said in a reply. He couldn't bear the thought of the only man who believed in him willingly passing into death. Snape couldn't help but think of the Pervell brothers, especially the youngest who willingly did the same. It hurt Snape to know he would lose a great friend, the school would lose a great Headmaster, and the world would lose a great wizard.
"You have to," Dumbledore stated as he turned around to his old friend. "But you have to know about Harry."
Snape rolled his eyes. They had the discussion about a part of Voldemort's soul attaching itself to Harry, creating an unwanted Horcrux, but Snape didn't really care right now. What he cared about was someone he loved and cared about asking for Snape to kill him.
"I know," Snape replied to Dumbedore's statement. "But I can't do what you're asking me to."
Dumbledore stepped up and put a hand on Snape's shoulder.
"When the time is right, I know you will."
Snape shook his head, but Dumbledore walked out of the room. Snape kept telling himself that when the time came, he would save Dumbledore as Dumbledore had helped him in the past. Nothing would stop him from saving Dumbledore. However, when the time really came, Snape did what was asked and Dumbledore's body fell off of the Astronomy Tower and landed with a thump on the ground. By the time he got outside, students were already crowding the body as tiny raindrops fell from the sky. Snape was thankful that it began to rain as to hide the few tears that slid down his face. He would be forever regretful of what happened that last night.
The End