The little plot of land just outside of Godric's Hollow was shrouded in darkness when the black-robed figure approached the slab of marble in its centre. The last time Severus had been at Harry Potter's gravestone - or should he say monument? - could not possibly have been more different from now than it was.
The last time he had been here, it was day, and the sun had been shining, without a care in the world. Tonight was overcast, further darkening the night that was only illuminated by the barest sliver of the waning moon.
Last time, there had been a crowd of thousands gathered at the piece of white marble, wanting to see the last of their hero. Tonight, Severus was alone.
Last time, he had been here as a soldier commemorating the loss of a comrade-in-arms (despite their personal differences), a leader figure, a symbol of hope. He was here as a teacher, a guardian maybe, regretting the loss of his charge who had given his life to save Severus' and many more instead. It was a social obligation to pay respects to the Boy Who Lived No More.
Tonight, he was a father, mourning his only son, the only son he had never truly known, and never would. It was a poor substitute, but Severus felt that he had to come here, to try at least to make some semblance of peace with his churning grief, to attempt to make amends even though it was far too late. Tonight, he understood the epitaph on the white marble: "Think of me, fondly, when we've said goodbye," it said, as did the diary's last words.
It was Harry's plea for his father to remember him for the boy he was.
Severus' black robes blended with the night once more as he knelt in front of the marker, the forehead leaning against it as pale as the cold stone itself, as if he would simply melt into it. His soul, certainly, felt as lifeless and cold - unwarmable - as the marble in front of him.
"Harry, I -" began Severus, before he choked on the words that were stuck in his throat and the tears that gathered in his eyes, tears he failed to blink away. He had no choice but to give himself fully to his grief as he had rarely allowed himself before, hidden behind layers of shields and masks. Here, in front of the cold, unmoving marble, he swore to himself he would not hide anymore from his son's memory, from his mistakes and regrets there was no escaping from.
And so the words burst from Severus:
"How, Harry? How can you call me the bravest man you ever knew, when I am too cowardly to even apologise to you, even if - even if it is too late, even if I know that - that nothing would ever set my mistakes right again? I wish - I could tell you how much I regret how I treated you when you were in my life, for so undeservedly hating you. I wish I had died in your stead, because you had everything to live for - you were young, you had friends, people who love you, you had a future! But I -"
Severus' voice broke. He continued more quietly, halted by sobs and hitches.
"Why did you save my life, Harry? Why? Because what you gave me, your sacrifice - It is like unicorn blood to me, your intentions too pure, for a - man, a murderer, like me! Do you know, Harry, what my life - this cursed half-life feels like? You told me to live, when I can not live with what I have done, because a lifetime - an eternity - of atonement would not be enough. No, it would never be. Not when I could not save you when I should have.
"When I found Lily dead due to my actions, I wanted to die, I desperately wanted to. But you lived, and so I still had a purpose, badly fulfilled as it was. Now -" Severus choked again. No hiding, he reminded himself. "I am too afraid to die, Harry, because that would mean facing you, and your judgement as well as your mother's. Even if you can somehow find it in yourself to forgive me, which would be more than I deserve… You fashioned me a hero in your journal - I am not. I have done nothing to deserve your admiration.
For many long minutes, the silence of the night was only broken by the quiet sobs of the man still leaning against the gravestone, and by the splashes of tears falling to the ground.
When his sobs finally quieted, he stood up, motions less fluid than they used to be, and stepped back. With a flick of his wand, a bouquet of everblooming poppies, forget-me-nots and asphodels appeared in front of the gravestone, the poppies red like blood - the blood of his son's sacrifice - against the pale colours of the other blossoms.
"I promise you, my son, I will never forget you."
With that, Severus turned and disappeared into the night.