The Fall Is What Kills You
Sirius fell. For a long time. He fell for so long he thought perhaps he'd always been falling. Of all the different ways he'd pictured death, an endless fall into nothing hadn't really been on the list. He vaguely recalled James telling him, after a particularly harrowing Quidditch match, "It's not the fall that kills you. It's the sudden stop."
James was wrong.
As he fell, he got lighter. First to go was the depression; next, the anger. After that, he lost the hate that had burned in the pit of his belly for so many years -- hate for Wormtail, Snape, Voldemort, the Ministry, his parents, and lastly, himself. It was gone, sloughed off like so much dead skin.
The next thing that went was his awareness of himself as a person. He had vague flashes of a big black dog, a cocky grin, a flying motorbike, but they fled from him as he tried to grasp them.
The only thing he had left was love. He remembered loving two boys with messy black hair and glasses -- one with a scar, one without -- a startling array of feisty redheads, and lastly, pale man with shaggy brown hair and sad eyes.
Just before he hit the bottom, Sirius -- or what was left of him -- finally grasped the true meaning of life. And then there was nothing at all.