He couldn’t very well deliver her to the convent in such a condition, and had gently escorted her upstairs and given her into the hands of the chambermaids, both of whom regarded her with some wariness, as though a tipsy nun was a particularly dangerous commodity.

He’d drunk a fair amount himself in the course of the afternoon, and more at dinner. He and Charles had sat up late, talking and drinking rum-punch. Not talking of anything in particular; he had just wanted not to be alone. Charles had invited him to go to the gaming rooms – Charles was an inveterate gambler – but was kind enough to accept his refusal and simply bear him company.

The candle flame blurred briefly at thought of Charles’s kindness. He blinked and shook his head, which proved a mistake; the contents shifted abruptly, and his stomach rose in protest at the sudden movement. He barely made it to the chamber-pot in time, and once evacuated, lay numbly on the floor, cheek pressed to the cold boards.

It wasn’t that he couldn’t get up and go to bed. It was that he couldn’t face the thought of the cold white sheets, the pillows round and smooth, as though Lillie’s head had never dented them, the bed never known the heat of her body.

Tears ran sideways over the bridge of his nose and dripped on the floor. There was a snuffling noise, and Plonplon came squirming out from under the bed and licked his face, whining anxiously. After a little while, he sat up, and leaning against the side of the bed with the dog in one arm, reached for the decanter of port that the butler had left – by instruction – on the table beside it.

The smell was appalling. Rakoczy had wrapped a woollen comforter about his lower face, but the odour seeped in, putrid and cloying, clinging to the back of the throat, so that even breathing through the mouth didn’t preserve you from the stench. He breathed as shallowly as he could, though, picking his way carefully past the edge of the cemetery by the narrow beam of a dark-lantern. The mine lay well beyond it, but the stench carried amazingly, when the wind lay in the east.

The chalk mine had been abandoned for years; it was rumoured to be haunted. It was. Rakoczy knew what haunted it. Never religious – he was a philosopher and a natural scientist, a rationalist – he still crossed himself by reflex at the head of the ladder that led down the shaft into those spectral depths.

At least the rumours of ghosts and earth-demons and the walking dead would keep anyone from coming to investigate strange light glowing from the subterranean tunnels of the workings, if it was noticed at all. Though just in case . . . he opened the burlap bag, still redolent of rats, and fished out a bundle of pitchblende torches and the oiled-silk packet that held several lengths of cloth saturated with salpêtre, salts of potash, blue vitriol, verdigris, butter of antimony, and a few other interesting compounds from his laboratory.

He found the blue vitriol by smell, and wrapped the cloth tightly around the head of one torch, then – whistling under his breath – did three more, impregnated with different salts. He loved this part. It was so simple, and so astonishingly beautiful.

He paused for a minute to listen, but it was well past dark and the only sounds were those of the night itself – frogs chirping and bellowing in the distant marshes by the cemetery, wind stirring the leaves of summer. A few hovels a half-mile away, only one with firelight glowing dully from a smoke-hole in the roof.

Almost a pity there’s no one but me to see this. He took the little clay firepot from its wrappings and touched a coal to the cloth-wrapped torch. A tiny green flame flickered like a serpent’s tongue, then burst into life in a brilliant globe of ghostly colour.

He grinned at the sight, but there was no time to lose; the torches wouldn’t last for ever, and there was work to be done. He tied the bag to his belt and with the green fire crackling softly in one hand, climbed down into darkness.

He paused at the bottom, breathing deep. The air was clear, the dust long-settled. No one had been down here recently. The dull white walls glowed soft, eerie under the green light, and the passage yawned before him, black as a murderer’s soul. Even knowing the place as well as he did, and with light in his hand, it gave him a qualm to walk into it.

Is that what death is like? he wondered. A black void, that you walked into with no more than a feeble glimmer of faith in your hand? His lips compressed. Well, he’d done that before, if less permanently. But he disliked the way that the notion of death seemed always to be lurking in the back of his mind these days.

The main tunnel was large, big enough for two men to walk side by side, and the roof was high enough above him that the roughly excavated chalk lay in shadow, barely touched by his torch. The side-tunnels were smaller, though. He counted the ones on the left, and despite himself, hurried his step a little as he passed the fourth. That was where it lay, down the side-tunnel, a turn to the left, another to the left – was it ‘widdershins’ the English called it, turning against the direction of the sun? He thought that was what Mélisande had called it when she’d brought him here . . .

The sixth. His torch had begun to gutter already, and he pulled another from the bag and lit it from the remains of the first, which he dropped on the floor at the entrance to the side-tunnel, leaving it to flare and smoulder behind him, the smoke catching at his throat. He knew his way, but even so, it was as well to leave landmarks, here in the realm of everlasting night. The mine had deep rooms, one far back that showed strange paintings on the wall, of animals that didn’t exist, but had an astonishing vividness, as though they would leap from the wall and stampede down the passages. Sometimes – rarely – he went all the way down into the bowels of the earth, just to look at them.

The fresh torch burned with the warm light of natural fire, and the white walls took on a rosy glow. So did the painting at the end of the corridor, this one different: a crude but effective rendering of the Annunciation. He didn’t know who had made the paintings that appeared unexpectedly here and there in the mines – most were of religious subjects, a few most emphatically not – but they were useful. There was an iron ring in the wall by the picture, and he set his torch into it.

Turn back at the Annunciation, then three paces . . . he stamped his foot, listening for the faint echo, and found it. He’d brought a trowel in his bag, and it was the work of a few moments to uncover the sheet of tin that covered his cache.

The cache itself was three feet deep and three feet square – he found satisfaction in the knowledge of its perfect cubicity whenever he saw it; any alchemist was by profession a numerologist as well. It was half-full, the contents wrapped in burlap or canvas – not things he wanted to carry openly through the streets. It took some prodding and unwrapping to find the pieces he wanted. Madame Fabienne had driven a hard bargain, but a fair one: two hundred écus a month times four months, for the guaranteed exclusive use of Madeleine’s services.

Four months would surely be enough, he thought, feeling a rounded shape through its wrappings. In fact, he thought one night would be enough, but his man’s pride was restrained by a scientist’s prudence. And even if . . . there was always some chance of early miscarriage; he wanted to be sure of the child before he undertook any more personal experiments with the space between times. If he knew that something of himself – someone with his peculiar abilities – might be left, just in case this time . . .

He could feel it there, somewhere in the smothered dark behind him. He knew he couldn’t hear it now; it was silent, save on the days of solstice and equinox, or when you actually walked into it . . . but he felt the sound of it in his bones, and it made his hands tremble on the wrappings.

The gleam of silver, of gold. He chose two gold snuffboxes, a filigreed necklace, and – with some hesitation – a small silver salver. Why did the void not affect metal? he wondered, for the thousandth time. In fact, carrying gold or silver eased the passage – or at least he thought so. Mélisande had told him it did. But jewels were always destroyed by the passage, though they gave the most control and protection.

That made some sense; everyone knew that gemstones had a specific vibration that corresponded to the heavenly spheres, and the spheres themselves of course affected the earth – ‘As above, so below.’ He still had no idea exactly how the vibrations should affect the space, the portal . . . it. But thinking about it gave him a need to touch them, to reassure himself, and he moved wrapped bundles out of the way, digging down to the left-hand corner of the wood-lined cache, where pressing on a particular nail-head caused one of the boards to loosen and turn sideways, rotating smoothly on spindles. He reached into the dark space thus revealed and found the small wash-leather bag, feeling his sense of unease dissipate at once when he touched it.

He opened it and poured the contents into his palm, glittering and sparking in the dark hollow of his hand. Reds and blues and greens, the brilliant white of diamonds, the lavender and violet of amethyst, and the golden glow of topaz and citrine. Enough?

Enough to travel back, certainly. Enough to steer himself with some accuracy, to choose how far he went. But enough to go forward?

He weighed the glittering handful for a moment, then poured them carefully back. Not yet. But he had time to find more; he wasn’t going anywhere for at least four months. Not until he was sure that Madeleine was well and truly with child.

‘Joan.’ Michael put his hand on her arm, keeping her from leaping out of the carriage. ‘Ye’re sure, now? I mean, if ye didna feel quite ready, ye’re welcome to stay at my house until—’

‘I’m ready.’ She didn’t look at him, and her face was pale as a slab of lard. ‘Let me go, please.’

He reluctantly let go of her arm, but insisted upon getting down with her, and ringing the bell at the gate, stating their business to the portress. All the time, though, he could feel her shaking, quivering like a blancmange. Was it fear, though, or just understandable nerves? He’d feel a bit cattywumpus, himself, he thought with sympathy, was he making such a shift, beginning a new life so different from what had gone before.

The portress went away to fetch the mistress of postulants, leaving them in the little enclosure by the gate-house. From here, he could see across a sunny courtyard with a cloister walk on the far side, and what looked like extensive kitchen gardens to the right. To the left was the looming bulk of the hospital run by the order, and beyond that, the other buildings that belonged to the convent. It was a beautiful place, he thought – and hoped the sight of it would settle her fears.

She made an inarticulate noise, and he glanced at her, alarmed to see what looked like tears slicking her cheeks.

‘Joan,’ he said more quietly, and handed her his fresh handkerchief. ‘Dinna be afraid. If ye need me, send for me, anytime; I’ll come. And I meant it, about the letters.’

He would have said more, but just then the portress reappeared, with Sister Eustacia, the postulant mistress, who greeted Joan with a kind motherliness that seemed to comfort her, for the girl sniffed and straightened herself, and reaching into her pocket, pulled out a little folded square, obviously kept with care through her travels.

‘J’ai une lettre,’ she said, in halting French. ‘Pour Madame le . . . pour . . . Reverend Mother?’ she said, in a small voice. ‘Mother Hildegarde?’

‘Oui?’ Sister Eustacia took the note with the same care with which it was proffered.

‘It’s from . . . her,’ Joan said to Michael, having plainly run out of French. She still wouldn’t look at him. ‘Da’s . . . er . . . wife. You know. Claire.’

‘Jesus Christ!’ Michael blurted, making both the portress and the postulant mistress stare reprovingly at him.

‘She said she was a friend of Mother Hildegarde. And if she was still alive . . .’ She stole a look at Sister Eustacia, who appeared to have followed this.

‘Oh, Mother Hildegarde is certainly alive,’ she assured Joan, in English. ‘And I’m sure she will be most interested to speak with you.’ She tucked the note into her own capacious pocket, and held out a hand. ‘Now, my dear child, if you are quite ready . . .’

‘Je suis prête,’ Joan said, shaky, but dignified. And so Joan MacKimmie of Balriggan passed through the gates of the convent of Our Lady Queen of Angels, still clutching Michael Murray’s clean handkerchief and smelling strongly of his dead wife’s scented soap.

Michael had dismissed his carriage, and wandered restlessly about the city after leaving Joan at the convent, not wanting to go home. He hoped they would be good to her, hoped that she’d made the right decision.

Of course, he comforted himself, she wouldn’t actually be a nun for some time. He didn’t know quite how long it took, from entering as a postulant to becoming a novice, to taking the final vows of poverty, chastity, and obedience, but at least a few years. There would be time for her to be sure. And at least she was in a place of safety; the look of terror and distress on her face as she’d shot through the gates of the convent still haunted him. He strolled toward the river, where the evening light glowed on the water like a bronze mirror. The deckhands were tired and the day’s shouting had died away. In this light, the reflections of the boats gliding homeward seemed more substantial than the boats themselves.

He’d been surprised at the letter, and wondered whether that had anything to do with Joan’s distress. He’d had no notion that his uncle’s wife had anything to do with the Convent des Anges – though now that he cast his mind back, he did recall Jared mentioning that Uncle Jamie had worked in Paris in the wine business for a short time, back before the Rising. He supposed Claire might have met Mother Hildegarde then . . . but it was all before he himself was born.