Sometimes, it feels like a century or more has passed since I came to haunt these halls; others, no more than a day. I mark time by the rhythms of the castle and the passage of the seasons, though winter's cold cannot touch me anymore than can the summer sun. Twenty years, perhaps, since betrayal brought me to my final, disastrous fall.
When the castle bustles with activity, I listen: to what the staff speak of quietly amongst themselves, to what the students say - and do not say - about the presence of the Dark Arts in the world, to the children and grandchildren of my former allies and sympathisers. I listen for a word, a breath, a hint that I am remembered - that some still revere me, longing for my return, and the return of the world I promised them. But as the years pass, the mentions grow fewer. None of these children fear, or even remember me. I have nearly as little substance in their minds as I do in the physical world.
Another summer comes. The castle is empty, but for house-elves, and a few professors and visiting scholars, taking advantage of the quiet to conduct their own research in the school's renowned library. They speak to one another little, except at mealtimes, and I am left to my own endless thoughts.
I drift out into the grounds, invisible in the sunlight, wondering for the thousandth time whether this pale immortality is worth clinging to. What hope have I for anything more than this? Perhaps I should let go - let myself fade away altogether - and discover at long last whether there is anything beyond this earthly life worth knowing about.
In the distance, a figure steps through the castle gates. Drifting closer, I see that it is a young witch, dressed in the plain black robes and wide-brimmed hat of a scholar. There is something familiar about her. Something that draws me to her. Curious, I follow her up the path to the castle.
On the threshold of the entrance hall, she hesitates. Her expression is furtive, as if she knows she should not be here. Instead of climbing the great staircase to the library, she turns and follows another familiar path, down into the depths of the castle.
At the door to the Potions classroom, she raises her wand. "Alohomora."
The lock clicks and the door opens. Grinning with impish delight, she slips inside.
The classroom is still and silent, waiting for the return of the students. Afternoon sunlight streams through the high, narrow windows that line the far wall.
The strange girl does not hesitate here. She strides with purpose to another door at the front of the classroom, and again taps the lock. The storage cupboard opens to her, revealing its wealth of gleaming jars, bottles, and boxes, stocked with every imaginable potion ingredient. The strong, musky scent of that cupboard is still sharp in my memory, though that sense is lost to me now. Only sight and hearing remain. I focus both on the mysterious intruder, trying to deduce who she might be, and what her purpose.
Stepping into the cupboard, she removes her wide-brimmed hat. Her hair spills out, silver and blue.
A memory stirs. Bright, fanciful hair. An impish smile. The metamorphmagus. Bella's blood-traitor niece, who was an auror. There is something of her in this girl. I dimly recall that she whelped for her werewolf mate in the final days of the war. A child with such colourful hair was a student at the school not so long ago. I paid it little mind. It was only a Hufflepuff. But surely it did not have the presence and vibrancy this girl possesses. I would remember that. I remember all the ones with the potential for greatness. I am certain I would recall if I had seen her before.
No, something about her stirs a different memory. Not of Bella's family, and certainly not of that sorry excuse for a werewolf. Something so familiar that it is almost a physical sensation, just beyond my grasp.
When she leaves the dungeon classroom, the stolen ingredients tucked into her pockets, again I follow, intrigued by the mystery of her, as I have not been intrigued by anything since I lived.
This time, in the entrance hall, she does turn to the great staircase, glancing around warily to make sure she is not observed. When she reaches the first floor, she pauses again, before proceeding down a familiar corridor, to the girls' toilets. There are toilets on the ground floor, and in the dungeons. There is no reason for her to come so far and so furtively, unless -
"Who're you?" a petulant voice demands.
The girl starts, then frowns at the ghost of a pigtailed and bespectacled child. I used to know this girl's name, when she lived. It is not important now. It never was. She is no one. My quarry appears to feel the same. Pointing her wand at the ghost, she says an imperious word. With a whooshing sound, the ghost girl flies backward, and disappears down a drain.
Striding to the sinks, the silver-haired girl bends her head, examining the taps closely. A glimmer of something like excitement burns in my mind. There can be no doubt about it. She knows the secret concealed within this room.
"Open," she murmurs.
With a grinding sound of stone on stone, the sink moves aside, revealing the entrance to a secret passage.
So the girl speaks Parseltongue - that rare magical gift of Salazar Slytherin, bestowed only upon his true heirs. Excitement growing, I follow her down into the darkness.
The light of her wand illuminates the passageway, but my kind do not need light to see by. It is dusty now, and littered with fallen stones. How long has it been since I myself first came this way, in search of my destiny and true inheritance? And now comes another, perhaps seeking the same.
As the girl approaches the end of the passage, her face shines with a mixture of trepidation and avarice. The light of her wand ignites sparks of emerald fire in the eyes of the intertwined serpents, carved into the stone with such artistic skill that they appear alive in the flickering light.
"Open," she commands again, and the serpents part, the stone wall splitting in two to reveal a cavernous space beyond: Slytherin's Chamber of Secrets.
Without hesitation, she steps through, her wand lighting a small circle around her in that great space. The high ceiling and the far end of the room are lost in shadow.
The light glints and gleams off white bone. Bending, she reaches out a hand to trace the curve of a great, empty eye socket, an expression of awed reverence on her face. I knew that the Potter boy had slain Slytherin's magnificent monster, but it is something else again to see those bones laid bare, just where they fell. Only the great, curving fangs are missing, taken for trophies no doubt. It is a bitter thought. I cannot help recalling my own sweet Nagini, the only living creature I ever had much care for in life. She, too, was slain by Gryffindor's sword, before my very eyes.
Rising to her feet, the girl spreads her arms wide.
"I'm here, Father," she says, eyes shining with fierce determination. "I've come at last."
So it is she. The child Bella and I created. I should have seen it at once. Those eyes, so like the ones that looked back at me from the mirror in my youth ... A strange sensation comes over me as I gaze upon this last living remnant of my own flesh and blood. I feel so little anymore, but this feeling is stronger than most: the sensation of having a mortal body - a connection to the world of the living.
Delphini, I call to her, remembering the name Bella gave her.
A quizzical frown furrows her brow. She turns her head, as if searching for the source of a sound. She has heard me. I am sure of it. And if she can hear -
"Father?" she calls, high and uncertain. The voice of a child.
I try to speak to her again, but the effort to make myself heard once has used up most of my strength. I can feel myself fading. It may be days before I am able to make my presence felt again.
But when she lowers her wand, shielding the light behind her hand, it is clear that she sees something. A faint glow or an outline, perhaps. A sense of my presence at the edge of her awareness.
She raises her chin, squaring her shoulders, proudly and fearlessly facing whatever she senses or sees. Her voice rings out. A declaration. A promise:
"If anything of you remains in this place, Father, hear me: I've come for you. I'm going to bring you back. And together, we'll build a new world."