On reflection, Minerva concludes that it did not start, as one unfamiliar with the chains of cause and effect might have deduced, on that night in the library. Nor did it begin five years earlier, in shouts and the shriek of high winds and the certainty that she had killed him, There must have been a time before that, she thinks-some seemingly insignificant moment that set the co-ordinates of their lives for intersection, But Minerva does not have the variables necessary to define such a moment, and no course of action to follow should she manage it. It would not ease her guilt, to know the moment when she ruined his life. It would not help him, either.

She does not sleep much anymore. For three years her dreams were too full of the dead look on a Eurasian's face; of the anguished eyes of parents staring from a newspaper's grainy photograph. My fault. The Chateau was too quiet at night and she took to playing Mendelssohn or Stravinsky, which kept her awake but filled the awful silence that throbbed in her ears and filled her lungs until she thought she would choke on it. Impossible. A manifestation of my guilt, nothing more. Then, when Artemis returned, she found she was used to the sleepless nights and the work and the music that kept her thoughts at bay.

"You could never have foreseen the consequences," Artemis tells her the first time she sees him, almost a year after his return. She's been putting it off; reluctant to face his family but needing the opportunity to observe him and gauge the damage she's wrought. "Butler says you've been blaming yourself. You mustn't." There are shadows beneath his eyes, blue-purple like rainclouds. He hasn't been sleeping either. Minerva tries to smile.

"Have I inconvenienced the fairies very much?" It's meant to be a joke, but her voice trembles, ruining the effect. Artemis doesn't notice. His face has gone tight suddenly and he fingers something that glints golden at his throat.

"I am no expert in the people's likes and dislikes," he tells her, casual voice at odds with the restless fingers above his breastbone, "I've had no contact with them in months. Not since July, to be precise."

July was when his mother had been ill. Minerva is not sure, exactly, what was wrong with her. She thinks of depression, of post traumatic stress disorder. What are the psychological effects of seeing your dead son come back to you after three years looking not a day older than when he left?

Artemis is staring out of the window, lost in thought. Minerva wonders if he hates her. She curls her hands around her elbows to hide their trembling and concentrates on the sound of his breathing. Alive and safe and here, despite me. The thought calms her a little. When Artemis breaks away from his contemplation of the manor gardens and turns his mismatched eyes on her, she is able to smile.

Gaspard Paradizo cares less for his daughter's intellect now and more for her health and sanity. He has heard of brilliant children who burn out, of teenaged girls who hide their lunches and write bright eulogies of self-loathing on their wrists. When Minerva first began to pour over her various projects until three in the morning and rise again at six, he tried lacing her evening drink with sleeping pills. Minerva detected a bitter aftertaste after the first sip, made several cutting remarks as pertaining to her father's intelligence, and then abruptly lost heart halfway through her tirade and drifted away from the table. Gaspard hired an award winning psychologist but Minerva was sceptical of his ability to help her even if she could tell him everything without being diagnosed with schizophrenia. Out of ideas, the good doctor merely hovers, occasionally taking a break from his worried contemplation to lay a hand upon his daughter's brow and ask her if she is feeling quite well. Beau absorbs the atmosphere without understanding it and becomes quiet and nervous, drifting from room to room like a small ghost.

Minerva finds their scrutiny more suffocating than the silence. In Fowl Manor the attention is not on her, if only because it is on Artemis. She knows, because Butler tells her, that his charge has taken to spending whole nights in the library. Occasionally, some time after he emerges, some multi-national industry will crash. Artemis Senior and Angeline begin to find excuses for Minerva to visit. When she is there he allows himself to be distracted, a little, by games of chess or heated discussion. Perhaps his parents think the distraction comes more from Minerva's yellow curls or the fine lines of her features, but Minerva doesn't think so. She finds that it calms her to have Artemis's voice in her ear or his face in the corner of her eye. He doesn't watch her like a boy; his gaze is generally sharp and thoughtful, plotting a rebuttal or, less often, a word of acknowledgment. She has caught him staring at her intently once or twice, though, as if he is looking for something in the angles of her face. Perhaps he wonders at her audacity, working her way so seamlessly into his life.

One night, more than two years after his return, she wakes in one of Fowl Manor's many guest chambers with the light of the full moon falling across her face. She lies heavy in the aftermath of a dream-she was thirteen again and in Butler's cottage by the sea. They were playing chess and he was losing; she was trying, without much success, to plug the holes in his technique.

Your task is to protect the King, she sighs at last, driven to simplicities, If you lose him, the game is over.

He turns away from her and the broken lines of chessmen, I know.

She picks up the ivory bishop that he moved out of harm's way, leaving his king open to attack. It twists and morphs in her fingers, solidifying into an effigy of herself, features aloof and arrogant. The pale king disappears from the board.

"The game is over," Butler echoes her words and walks out of the cottage.

The metaphor is crude and rather less than Minerva would have expected of her subconscious, but she finds further sleep beyond her nonetheless. She pulls on a blue dressing gown and steps onto the dark landing. She lets her feet take her where they will and is only mildly surprised when she finds herself at the entrance to the library, where a soft light illuminates the wide oak bookshelves. Someone else is awake this moonlit night. She tells herself it could be Artemis Senior, or even Myles, but after months of visits she recognises the breathing.

Artemis sits at a low table, his hands fisted in his hair. Pages of his elegant handwriting litter the desk before him. Minerva recognises theorems and formulae that have baffled scientists for years, interspersed with lines of what looks like poetry. It looks like genius, or madness. She comes close to him, close enough to feel the warmth of his body, and stops.

"What are you doing?"

He does not look up, but one arm sweeps the papers from the table. They flutter to the carpet like stricken birds, "Nothing of any significance, to myself or the general populace."

Minerva nods, understanding. How many nights has she spent on proofs and equations for no other reason than to fill the empty hours? She drops to her knees-in his low chair his face is on a level with her own. Through the cage of his arms she can see that his cheeks are flushed and his eyes bright. Did I do this to him? She wonders, Did those stolen years turn his brilliance into insanity? Then, I have caused so much harm here, does it really make any difference if I am to blame for this as well?

He looks feverish. She puts one cool hand to his forehead, beneath the feather-soft sweep of his hair. He turns to her on instinct, reacting to the touch, and the flat of her palm is against his cheek; her thumb brushes the corner of his mouth. When he speaks his voice runs through her like the wind through an empty house, stirring curtains and dust motes, the illusion of life.

"I'm so tired," he says.

I know, she wants to reply, I know, but somehow the space between them is gone-though distance cannot be covered save through movement, so one of them must have moved, though she does not remember it-and she shapes the words against his mouth instead. Her other hand comes up to hold his face and he goes very still against her. Then he moves and it's like the tides, following the inevitable tug of the moon; it drags on them like gravity and they fall into the dark.

I'm sorry, she mouths against his skin, over and over, I'm sorry I'm sorry I'm sorry. And once, long after the momentary gasp of pain that could have prompted such a response, she thinks she hears him say it too. But her hearing can hardly be said to be perfect under this assault of her other senses, and anyway, she muses later, as Artemis rewrites the library's camera feed, Artemis certainly couldn't want forgiveness from her.

They come together after that, not every night but often. He never touches her during the day, embraces her only formally at the end of every visit. Minerva analyses her emotions and concludes that this does not upset her. She wants to hold him close and feel the life in him; she wants the heady rush that fills her head, drowning out the guilt there. She neither wants nor deserves saccharine nonsense or the promise of a lifetime that stretches too long before her/. She suspects that Butler knows what is going on; he would know if a spider set foot in his precious boy's room, let alone a girl. But he says nothing, though he sometimes looks at her with something that resembles pity. She wonders what Artemis takes from their late night rendez vous, what he forgets, or is forgiven, as they lie together in the darkness.

She finds out, eventually. She is a genius after all.

It is the dark of the moon and Minerva is walking in the garden. Her flight home is tomorrow and she will go to Artemis soon, but she is delaying the moment with something close to masochism. She will spend the next three months unable to reassure herself of his vitality by tasting his breath and listening to his heartbeat, after all-she should be able to spin out a few hours.

The garden is mostly shadow, but close to the house itself are motion-sensitive lights that flicker on as Minerva approaches. They come on suddenly and she blinks at the sudden illumination of a tree, a walkway, the corner of a croquet pitch…and a small figure with its head tipped back, gazing up at a window set high in the manor wall. In the next second the figure shimmers out of existence, but Minerva stumbles forward and holds out her hands, grasping at the space where it had been.

"Fay?" she calls, "Are you looking for Artemis?"

Silence and shadows. Minerva tries again.

"I have met with your people before. My name is Minerva…"

"I know your name, mud girl," a voice replies in perfectly phrased French. Minerva reaches out and a figure steps out of the darkness. She recognises the pretty face and the cropped reddish hair. But the eyes, red and swollen, make her heart stutter like a bungled symphony. Blue and hazel. Artemis has explained his heterochromia to her as a result of his return from the demon lands, but he had seemed reluctant to go into the details and she hadn't pressed him. Now there is this, and Minerva knows the window this fairy-woman was staring at. Understanding begins to break like the toppling crest of an ocean wave.

I've had no contact with them in months, he had said, with the same look in blue and hazel eyes as she was seeing now.

"How many nights?" she speaks softly, as she would to an animal that might bolt from her at any moment, "How many nights have you looked for him?"

The fairy woman does not answer, though Minerva sees the muscles of her jaw clench.

"Sometimes he stands at the window and just stares out into the night," she goes on, "He can spend hours like that. And I always wondered what he was looking for, but now I know. He hasn't forgotten. Not in three years." And that isn't so long, she thinks, wondering if there is pain here that will hit her later, I waited three years for him, after all.

The figure with the mismatched eyes is still staring at her with something close to hostility, and Minerva makes another connection. "It's my fault he was gone, those three years. I spent them thinking I was a murderess-melodramatic I know, but I was young and impressionable. These years left their mark. I spent so long waiting for him to come back, and when he did I never quite believed it. I think I needed to remind myself he was real. And both of us were very lonely," she laughs and the sound is bitter in her own ears, "Hardly admirable behaviour. But you can make him happy now. And then maybe I can sleep at night."

The fairy woman watches her for another long moment, and then touches the inside of her own wrist. Fragile wings that Minerva has not noticed until this point whir into action on her back, and she rises two feet into the air to look into Minerva's eyes.

"Thank you," she says, and her voice is sweet and warm, like one of Mama's lullabies but layered somehow, "That was a good thing you did, Minerva. You should be happy. But first you should go to bed. Aren't you sleepy?" Minerva does feel sleepy all of a sudden- sleepy, not tired, in a way she hasn't been since she was a little girl and would climb into her mother's lavender-scented embrace and doze in the evening sunshine. She turns away from the fairy woman and wanders back to her room. Sleep is instant, deep and comfortable.

In her dream she is thirteen again and outside Butler's cottage by the sea. They are skimming stones, which Minerva is not good at. She can work out the angles and projectiles necessary to make a stone rebound off the surface tension with maximum efficiency, but her hands are clumsy and feeble. Butler's record is seven jumps. She has yet to achieve two.

"This is not my forte," she admits, blushing a little. The ageing bodyguard smiles and fingers the pebble in his hands, flaws worn smooth again by water and time.

"Try again," he says, handing her the stone, "Forget what's happened up till now. Clean slate. Let's see what you can do."

She throws. The stone strikes the water and sinks. There is a moment of silence, and then they both laugh, a proper laugh that clears Minerva's head and fills up her chest, untying the knots there. He puts his arm around her shoulders and they head back to the cottage, to an evening of tea and scones and perhaps a chapter or two of Gone With The Wind. Behind them the tide comes in, washing away their footprints and leaving the stretch of sand as smooth as a blank page, a clean slate.

A new start.