'I've only seen her in photos. She's a gilder.'

'What is that, a gilder?'

'She adds gold decoration to things, gold leaf on frames, and monuments.'

'Too cool!' Chloe said enthusiastically. 'Wait, they're calling me. I'll have to go. Tell me all about it over dinner on Thursday,' and she promptly hung up.

When Laurent went home his apartment struck him as empty and silent in a way he had never felt before.

The second evening he again poured himself a Jack Daniel's and lit the fire. William rang, as they had agreed, on Laure's landline 'at cat time'. When he asked if Laurent had been to see her, Laurent had replied: 'Yes'. This time the question had obliged him to move to the next level, that of the outright lie. Then Laurent had settled down on the sofa and the cat had installed itself on his lap and started to purr as he stroked it gently. He told himself that this could not go on, that he had crossed the line some time ago. From having performed a fine act of citizenship (as the police put it), he was now sitting by Laure's open fire, which effectively made him guilty of breaking and entering. His amateur investigation had worked like a dream and when it came to an end which it inevitably would he would wonder whether these past few days had actually happened. For now, he felt rea.s.sured by the unfamiliar decor with its soft lighting and had no desire to return home. He had not experienced such a sense of peace for many years; time seemed to have been reduced to the rhythm of the crackling fire. Just as he was falling asleep he persuaded himself that he could spend the rest of his days here on this sofa, a black cat asleep on his lap, waiting for an unknown woman to wake up and return.

He found himself on the terrace of the tower at La Defense. It was a bad dream that recurred every two or three years. A dream that wasn't exactly a dream. The terrace must still exist. It was from another life. A life in which he was Laurent Letellier wealth adviser private banking. A life which had ended on the thirty-fourth floor of a tower in a business district, one summer afternoon at the end of the twentieth century. After a long meeting, everyone had been drinking coffee in the sunshine of the tower's terrace cafe. His colleagues had taken off their jackets and loosened their ties; some had even put on sungla.s.ses. Laurent left the group and went over to the steel guard-rail. He looked down at the figures in the square below, preceded at that hour by enormously elongated shadows. Some were moving slowly, others trotting briskly like ants surely towards a meeting which they must not be late for. The air was burning his skin, the tower blocks bright in the sun and sharp like quartz rising from the earth. He lowered his head towards the 140 metres of emptiness. He thought it would only take a few seconds. His colleagues would be stupefied; some would drop their coffee cups, others would open their mouths wide without emitting any sound. He would leave behind the young woman he had just met, Claire; she would remake her life with someone better than him. Many years later she would remember that sad relationship she had started with the boy who had killed himself without leaving a letter of explanation.

An existence devoted to reading would have been his ultimate fulfilment, but it had not been given to him. He would have had to choose that path much earlier, to have known what he wanted to do straight after the baccalaureat. To have had a life plan. Laurent had let himself be drawn into studying law, which had led to the bank. At first it had been interesting to be recognised as a promising young banker, to climb the hierarchy, to have responsibilities and to earn a lot of money. Up until the day he had started to feel, dimly at first, then more and more clearly, that the man he had become was the absolute opposite of what he really was. Although the dichotomy weighed heavily on him, for a while the money he was earning was compensation enough, but then it could no longer make up for it. The gap between his ideal and his reality was too great. The weight turned into an anguish which was succeeded by the intolerable idea that he was wasting his life or even that he had already wasted it. Laurent backed away from the railing then turned towards his colleagues. He contemplated them, aware that something momentous had just taken place: he had coldly considered climbing over the railing of an office block at La Defense.

'I'm going to change jobs,' he told Claire that evening without telling her about the strange impulse that had come over him as he stared into the void. 'I'm going to open a bookshop.'

She had spoken to him for a long time about it, had asked him to think about it carefully. Then she had said nothing more. Laurent had negotiated an amicable departure from the bank. Claire was promoted; the word 'deputy' was no longer appended to her t.i.tle as marketing director of a frozen food brand. Laurent had bought the commercial lease of the Celtique, and the same week, Claire had announced that she was pregnant. A new life began.

The end of the dream never changed: he climbed over the railing and as the thrill of the fall took hold of him, he woke up. The cat leapt from his lap. The phone in the study was ringing. Laurent rose and went into the room. The answer phone had been activated. A b.u.t.ton with a little envelope on it began to flash on the keypad, then stopped. Laurent hesitated then pressed on the envelope.

The loudspeaker said, 'You have one new message. Message received at 8.46. "Good evening, Laure ... It's Franck. I haven't heard from you; you're not answering your mobile, so ... I know I was awkward last time, but ... well, it's up to you. This will be my last message ... I won't call again if you don't ring me. So that's it." To listen to the message again press one, to save it press two, to delete press three.'

Laurent looked at the machine and pressed three. 'Your message has been deleted. End of messages. To return to the main menu press nine; for other options press two.'

'Helene ... Helene, look ... the line on the monitor's rising. I'll stay with her,' said a female voice.

'Call Doctor Baulieu,' replied another woman's voice. 'Tell him there's movement in the left hand.'

A p.r.i.c.kling sensation. Vague at first before she pinned it down. The tips of her fingers and toes. She had gradually become aware of her own body again. She could hear the blood beating more and more loudly in her ears. The vast, sweet universe she had been floating in had shrunk to fit within a single room. Although everything remained dark, she could sense she was in a s.p.a.ce enclosed by walls and a ceiling. Her mind could roam around the room; it didn't take long to explore. Wherever she was, it was a quiet place to be lying in. She opened her eyes. Everything looked blurry, too bright and fuzzy, like a camera out of focus. A shadow moved towards her, hazy around the edges as if behind frosted gla.s.s.

'h.e.l.lo,' said the shadow. 'You're waking up.'

The shadow came closer. Its face was still blurred but she was beginning to make out eyes, a nose, a mouth and blonde hair. She had heard this woman's voice before, while she was asleep.

'Don't worry,' she said, 'there's no lasting damage. You're not hurt.'

Her mouth was not moving in time with the words. The sound was a good second behind.

'Everything will look a bit fuzzy,' said the blonde shadow. 'Don't try to talk. Blink twice if you can hear me and understand what I'm saying.'

Laure blinked twice.

'That's great,' said the shadow encouragingly. 'You're coming out of a coma. You've been in hospital for two weeks. Do you understand?'

Laure opened her mouth to reply.

'Sshhh,' said the shadow, putting a finger to Laure's lips as if to stop her spilling a secret.

'Close your eyes,' she said softly, 'and try to take in what I've just told you. Take your time. There's no lasting damage. You're not hurt,' the voice repeated before placing her hand on Laure's. 'I'm right here, I'm not going anywhere. Everything's fine.'

'I'm your doctor,' said the head with white hair, which was a bit less fuzzy than the woman's face. 'Don't try to answer. As the nurse told you, you're doing well. Can you nod your head? That's good. I'm going to ask you a few questions and you can nod like that to answer. Can you see a little more clearly now than when you first woke up? Good. Is there a delay before you hear my voice? Good, that's normal; it'll pa.s.s. Wiggle your left foot, very good. Right foot, perfect, your right index finger, no, the index finger, thank you, your left little finger, and again, very good, breathe in, breathe out, perfect. Now we're going to say a sentence: the robin is sitting on the branch. Off you go.'

Laure repeated after him, her voice hoa.r.s.e.

'What a lovely voice,' commented the doctor.

Laure made a face.

'I'm going to ask four questions that may seem a little strange. Are you ready?'

Laure nodded.

'Can you tell me the name of a cuddly toy or doll you were especially fond of as a little girl?'

'Foxy,' whispered Laure after a pause.

'Good,' said Baulieu. 'Presumably Foxy was a fox?'

Laure nodded.

'Where were you on 11 September 2001?'

'In Kuwait ... gilding ... the palace of Prince Al-Sabah.'

Baulieu shook his head.

'That's a first,' he said. 'Never heard that one before. What's your name?'

'Laure. Laure Valadier.'

'Last question: do you know why you're here?'

'My bag ...' she murmured.

'Don't talk too much,' said William, stroking her hand. 'You mustn't wear yourself out.'

'Thank you for being here. What about Belphegor...?' she asked in a whisper.

'Don't worry, he's fine. Laurent took care of everything.'

'Laurent ... Who's Laurent?'

At the very moment Laure was asking that question to which William replied with an uneasy silence Laurent was pushing open the cast-iron gate to three large courtyards that led on from one another. They had both agreed during the 'cat time' phone conversation the previous evening to meet the following day at the workshop so that Laurent could return the keys. As he was looking around for the sign indicating which workshop was where, his gaze was attracted by a paving stone in the courtyard covered in gold. There was another one a few metres away and further on a third one. Like a fairy-tale trail, all you had to do was follow the golden stones to the third courtyard and the gla.s.s frontage of the Ateliers Gardhier. A curly-haired woman wearing little gold gla.s.ses was smoking a cigarette in front of the door. She wore black jeans and white Repetto pumps. Laurent said h.e.l.lo to her as he entered the building, where he found himself in a vast hallway whose walls were covered in ladders, ropes and tools that he did not recognise.

'Can I help you?' the woman asked him.

'Yes, I have a meeting with William.'

'I'm sorry, he's not here,' she said, blowing her cigarette smoke into the light.

'Oh.' Laurent was disconcerted. 'I was supposed to return Laure's keys to him. Laure Valadier?'

'You're a friend of Laure's?'

'Yes, I was feeding her cat.'

'It's Laure he's gone to see. The hospital called, she's just come round.'

'How is she?'

'I think she's fine, but William didn't go into detail; he left very quickly. He was very anxious. Well, you know what William's like ...' and the woman ended with a rueful smile.

'Good, that's very good,' murmured Laurent. 'Everything is very good,' he added in a low voice as if just to himself, then he smiled back at the woman. 'Could I ask you a favour?' he said, taking the duplicate keys out of his pocket. 'Could you give him Laure's keys?'

'Of course,' she said, stubbing out her cigarette. Laurent handed over the keys, said goodbye and went out into the courtyard, following the golden paving stones. He knew what he had to do: he had to put out of his mind those two extraordinary days and the illusion of being with the woman he must never now meet. How would she accept the fact that a stranger had inveigled himself into her home, had fed her cat and pa.s.sed himself off as her lover? He himself would have difficulty explaining his actions if by chance anyone should ask him to justify them. To the questions: Why did you personally try to find the owner of the bag? Why did you wait for an author in a park two days in a row? Why did you pay Aphrodite Dry-cleaner's with your own money? Why did you not correct Laure's friend when he took you for her lover? Laurent could only answer truthfully, but unsatisfactorily: I don't know.

'So it appears I let in an imaginary man who fed a real-life cat for two days,' William concluded.

Laure and Baulieu were watching him in silence.

'Have you seen him again since?' Laure asked.

'No,' William replied weakly, laughing nervously at how ridiculous his answer sounded.

'I'm sorry, William, but I don't know any booksellers called Laurent,' Laure said.

'Right, I think we'll leave it there,' said Baulieu. 'I'll be back later this afternoon.'

'And I'll be back tomorrow morning,' added William. 'Get some rest,' he told her, stroking her hand.

'We need to find out who it was, don't we, William? Will you let me know who it was that came to my flat?'

'Yes, my lovely,' he said, planting a kiss on her forehead. 'Don't fret, everything's fine.'

Laure smiled and turned to look at the ventilator beside the next bed. The sound it made was hypnotic, soft and repet.i.tive. Perhaps this was what had inspired the running water in her dream?

William and the doctor went out into the corridor.

'No.' Baulieu stopped him before he even had the chance to ask the question.

'But, doctor, I really think ...'

'No,' Baulieu said again.

'She has no memory of the man she's dating. She must be suffering from amnesia.'

'One more time: no, Laure does not have amnesia. I'm sorry, but we've carried out all the tests. I don't have an explanation, but as far as I'm concerned it's not a medical issue.'

There was a heavy silence. It seemed to William that however 'unique' Baulieu's sense of humour, he was currently displaying none at all. His tone was almost cold, in fact, and he seemed anxious to draw the discussion to a close.

'Call the man and ask him who he is.'

'I don't have his mobile number,' muttered William. 'Or any other way of contacting him.'

The hospital and the Ateliers Gardhier were seventeen Metro stops and a change of line apart. As the stops went by, William came up with a string of ever more outlandish theories: from potential burglar, he was now suspecting Laurent of being some kind of apparition. The criminal hypothesis had gone out the window by the third station. Laurent was dressed very respectably and certainly didn't look as if he was hiding a crowbar inside his coat. He also knew Laure's full name. And not only hers, but the cat's. Plus he knew that Laure had met a famous author and asked him to sign her book. In short, he knew Laure, even if she didn't remember him. Yet Baulieu wouldn't entertain the idea of amnesia. I'm the only one who saw him, William told himself again and again. All attempts at a rational explanation seemed to defy logic.

At the fifth station, he typed the words 'acid flashback' into his iPhone and clicked on a Wikipedia article: 'Term first used as part of a 1965 study carried out by William Forsch, a psychiatrist at Bellevue Psychiatric Hospital in New York. Forsch observed that some users of LSD reported effects reminiscent of those caused by the drug several months after taking it.' William had taken magic mushrooms on three occasions. Following the last of these, four years ago, he had spent the night lying in his bathtub talking to the shower head, which talked back. The pair had enjoyed a philosophical discussion of a rare intensity, spanning such universal themes as death, the afterlife, the possibility of life on other planets and the existence of G.o.d. The shower head came up with precise answers to all these questions. The following morning, William had to concede that the intellectual capacities of his bathroom fittings had severely diminished, and the shower head's gifts were now limited to the provision of hot or cold water in cla.s.sic or ma.s.sage mode. That episode had marked the end of his experimentation with mind-altering substances. But neither this nor his previous dalliances with drugs had resulted in a man materialising and striking up a conversation. The Wikipedia article alluded to the possibility of short-lived disturbances in the months following a trip, not years afterwards. The theory did not hold water.

As he walked through the tunnels to change trains, he found himself considering a paranormal explanation. Sitting on one of the seats along the edge of the platform, William imagined that Laurent was the ghost of a long-dead former occupant of the flat after all, the building dated from 1878 it said so above the door. He had seen a film a bit like that, with Bruce Willis and a little boy who saw dead people. And there was Ghost, of course, with Patrick Swayze and Demi Moore, one of the most romantic films ever made, and Patrick Swayze was unbelievably hot in it even playing a ghost. All he could think of were Hollywood movie plots, imaginary stories dreamt up by screenwriters. Nothing real.

The train pulled in and as it travelled to the next four stops, William toyed with the idea that Laurent could be the physical manifestation of a man travelling in an astral plane a kind of lama figure whose body was in a whole other realm, and who intuitively knew everything: the name of the cat and the owner of the apartment, as well as recent events in her life. But the theory was too muddled and Tibetan and he knew nothing about astral travel or the mental capacities of lamas. At the eleventh station, he recalled a doc.u.mentary he had watched a few months ago about an early-twentieth-century priest, Padre Pio. Not only had the holy man received Christ's stigmata, but he also possessed the gift of ubiquity, or 'bilocation', as the doc.u.mentary put it. Padre Pio was said to have been in several places at the same time, and these places were many thousands of kilometres apart. There were eyewitness accounts to back this up. Despite having kept quiet initially, the Church took the unexpected step of declaring the claims to be genuine.

Grappling with such mystical questions in the middle of a Metro carriage planted two spine-tingling words in William's head: guardian angel. After all, it was while he was in the grip of the cat-feeding dilemma, with no one to stand in for him during his trip to Berlin, that the doorbell had rung. The visitor had agreed to feed the cat while he was away, as if that was exactly what he had come up to the fifth floor to do. To help them, him and Laure. As if that had always been his mission.

William was weighing up the probability of an angel making a visit to central Paris when the warning sound signalled the doors were about to close at his stop. He scrambled to his feet and ran onto the platform. No, none of it added up, angels, lamas or phantoms. Besides, he remembered Laurent had been due to come and drop off the keys that morning, which meant someone else might have seen him. That put his mind at ease, and he left his wild thoughts behind him as the escalator returned him to street level.

He had barely crossed the threshold of the ateliers when he b.u.mped into Pierre carrying a heavy gilt picture frame.

'So,' asked Pierre, 'did you see her? How is she?'

'She's doing well, the doctor's happy, she sends her love to everyone, she should be out in four days.'

Pierre shook his head. 'She's had a close shave,' he said.

'Oh, Pierre, did I have any visitors this morning?'

'No, I didn't see anyone.'

William carried on past Agathe, who was stirring her Armenian bole mixture in front of a contemporary sculpture which was to be entirely covered in gold leaf. She turned to stop him.

'So, how is she?'

'She's doing well, she's conscious, the doctor's happy, she sends her love to everyone, she should be out in four days.'

'Phew,' said Agathe.

'Oh, Agathe, did someone call for me this morning?'

'No, not as far as I know.'

Franois came towards them, his finished pipe still clenched between his teeth.

'So, did you see her?'

'Yes, she's doing well, her doctor's happy, she sends her love, she should be out in four days.'

'That's what I like to hear, my boy,' said Franois.