Note: Oops, I wrote another not planned, sad HP oneshot.
The idea is that Harry didn't find out about his scar being a Horcrux until late in the war, and Dumbledore wasn't sure that he'd live. The song lyrics are left at the end purely because it makes everything much more confusing.
They stand still, each aware of the fragile thing they hold in their hands.
Harry shrugs slightly, the darkness of the corridor showing only the shadow of his features.
Severus looks at him, shifting through the gloom to see the weariness and resignation on Harry's prematurely aged face. "Why?" he asks quietly, because he has to know, even now.
A candle in the room behind Severus flickers and goes out, casting half his face in shadow.
"Because if I can't do it now, then I never will be able to again."
Severus raises his face from the study of the floor it had begun while Harry spoke. His dark eyes show the most clearly in the surrounding darkness. They are guarded, careful.
"Is that the only reason?"
Harry lets out a slow breath. "No," he admits, too loudly to fit in with the shadows. "No. I came... because... well, it could be the end, couldn't it? It feels right to be with the person I love, at the end of days."
Harry's eyes burn bright, hopeful and loving, trying to combat the darkness surrounding them both.
"Love? That did not seem to be your general feeling toward me, when you left." Severus' voice is blank, and he goes with his instinct to try to sink into the dark.
Harry looks down. "I... I did love you, then. I just needed someone to blame. It was so hard to take in the information, about the Horcruxes, and my scar... and I took it out on you. I'm sorry." He looks up once again, eyes burning holes through the gloom. "I'm so sorry."
"Did you not consider the fact that I was also taking in the information? That I was trying to deal with the fact that there was a very great possibility that my lover would have to die to bring down the Dark Lord?"
"No..." Harry says slowly, hunching his shoulders. "I got so upset... and I just assumed you wouldn't care..."
"Not care?" Severus says, disbelieving. "Not care that you would die, Harry? Obviously your opinion of me has not been changed since your school years."
"No! No, it has! I was just depressed, and insecure, and I'm really, really sorry that you took the brunt of it. I can never do anything to take that back."
"And yet you have come here, the night before the battle."
Harry holds out his hands as if he were trying to touch Severus' arms, in an unconscious gesture of desperation.
"I came to see if I could make it right, to stop the hurting, to stop you hurting. To show my love on the night before the day that determines whether anyone will be able to love ever again."
The clouds shift away from the moon, allowing a sliver of moonlight to bathe the room through the window directly behind Severus.
"I love you," Harry says quietly, looking into Severus' eyes. "I'm sorry I haven't shown that. I'm sorry that it took until it was my last chance to show it for me come to my senses."
They stand still, each aware of the reawakened possibility they hold in their hands, while the moon bathes both their faces in a strange, pale glow. They hold each other's eyes silently, dark and green, both dulled with exhaustion and grief.
Severus moves first, opening the door to his rooms further, and moving to the side to give Harry space. "Welcome back," he says, and Harry's grateful smile lights up the room all by itself.
Look down - the ground below is crumbling It's the last day on earth
Look up - the stars are all exploding
In my dreams
It's the end of the world
And you've come back to me
In my dreams
It's the last day on earth
-The Last Day on Earth by Kate Miller-Heidke