Alice took a few breaths of the steamy, underground air and tried to calm down. It didn't occur to her to be afraid, but she was bountifully annoyed – annoyed enough that you could have felt sorry for the big, clanking armoured woman beside her, and all the terrifying demons she might meet down here in the dark.

Jack hadn't given her much choice about coming here. He'd enlisted one of his beastly henchmen to chloroform her and have her brought to the caves. The chloroform had been a spiteful touch, perhaps. He remembered how angry it had made her the first time. 

Either way, he hadn't stuck around to observe its effects. When Alice came to, she was bound and gagged. Her back was pressed up against jagged rock, sweat was beading on her forehead, and a large, armour-plated woman was standing over her, sizing her up. 

"Jack said to explain the mission before I removed your gag," said the woman. "But I don't see why that's necessary." 

Alice raised her eyebrows, but did nothing to disillusion the foolish woman. She sat determinedly steady while her gag was removed, and then said, "Untie the rest of my bonds right now," in the calm, authoritative voice which usually had people scurrying to oblige her. 

The woman just pursed her lips, as though patiently enduring an insult. 

"I'm Val," she said, after a frosty pause. "I'm not with Jack Cade – I hate him – but he says there could be a woman still trapped down here." 

Alice gave a languorous shrug, pretending she wasn't disconcerted to find that her voice didn't work on this woman. "He just wants me out of the way. He knows I'm the only one who could possibly control him." 

"Her name's Mathilde Marron," said Val, as though she was determined to get through her explanations, no matter how many times she was interrupted. Alice supposed that made sense, for such a big, lumbering creature. Once she had gathered momentum, it probably took a long time for her to stop. "And the incentive he gave me for finding her is that she's the only one with the power to kill him – just like you're the only one with the power to kill the gargoyles." 

"Ridiculous," said Alice – though she remembered Jack's pale, pinched, otherworldly appearance in the mortuary. She remembered thinking he looked as though he had died already, and it would take someone very special to put a stop to him now. 

She held up her bound wrists and gave Val a meaningful look. "Any objection to untying me now I've heard you out?" 

Val pursed her lips again. She wasn't happy, but she appeared to have a grudging sense of honour, because she grabbed Alice's wrists and wrestled with the ropes.

When she was free, Alice put a little distance between them – the woman reeked of armour polish – and paced around, trying to smooth out the stiffness in her back.

The fire-mines would be even more stupid than Oxford, she knew it. Steeped in just as much prejudice and illogical thinking. Things that would want to fight her and eat her. And, if she was really unlucky, they might talk about sparing her because she was a woman first.

The only sources of light down here were red gems half-embedded in the rock. They reflected in Val's breastplate, giving her an appropriately Stygian glow. 

"Is it true you stopped a demon from raping Ellini by throwing hymn-books at it?" the woman asked.

Alice drew herself up disdainfully. "It wasn't the hymn-books but the firm, authoritative tone of voice that caused the demon to stop. If I had been allowed to continue, there would have been no rape, no fire, and certainly no beheadings. But, unfortunately, the demon's master didn't know what was good for him-"

"And clamped a pad of chloroform over your mouth," said Val, as though this was her favourite part of a well-loved story.

"Yes," said Alice icily. "And, since then, it seems everyone has been behaving like a barbarian." She cast a look at Val's armour. "Dressing like a barbarian, too..."

Val looked down at her breast-plate. "It's probably more practical than what you're wearing, down here."

"Well, I didn't know I was going to be down here, did I?" said Alice. She settled on an outcrop of rock and made an effort to study her new companion. Perhaps she wasn't all hopeless. At least she was helping to dispel the myth that women were gentle by nature.

"What about you?" she asked at last. "Do you really mean to do Jack's dirty work for him? Find this Matilda?"

"Mathilde," said Val, shifting her gaze from her boots to her massive knuckles. "She's French. He was quite insistent about that, for some reason. And if I find her, perhaps I'll bring her back with me. But when I find the gargoyles, I'll kill them all."

"You may find that difficult, since I'm the only one with the power to kill them."

The woman gave a contemptuous shrug. "I'll just hit you over the head and use your arm to stab them, like Ellini did."

Alice glared. This wasn't something she liked to be reminded of.

"Oh yes?" she said coolly. "And how will you find them? Bang your sword against the rocks until they come blundering out of hiding? You need someone with a functioning brain. And since it's the natural order of things that the brain informs the muscles, I'll be deciding who we kill."

Val looked for a moment as though she was contemplating drawing her sword – not that there would be room to wave four feet of metal under the cavern ceiling – but her sense of honour seemed to win out. 

"I don't know why you should take it so personally, anyway," Alice muttered. "Does it bother you, what was done to the women down here?"

Val stared at her. "Doesn't it bother you?"

"Of course. But it's already happened – there's nothing we can do about it now. And I won't have their suffering used as an excuse for more barbarity."

She hesitated, weighing her own curiosity against the woman's probable temper. But the only way to control her was to understand her, and she couldn't have a huge, metal-plated woman on the rampage down here, so she went on:

"Why does it bother you? Because you were Miss Syal's gaoler for four years? Isn't it rather hypocritical to resent the other people who locked her up?"

Val shrugged again. It heaved her entire breast-plate up and then down again. It took a good while for everything to settle, and Alice considerately – for all that the girl would notice consideration – averted her eyes. 

"A gaoler has to keep her charges alive, everyone seems to forget that. And she wasn't the easiest person to look after. When she was wrapped up in her books – or, worse, in her memories – she forgot to eat. I practically had to spoon-feed her. She never appreciated anything you did, unless you bought her a book or took her to a library, but she wasn't right in the head, so I didn't mind that. I didn't even really mind it when she ran off with Jack and left me for dead on the steps of the Bibliotheque Mazarine. But for him to get her killed like that – for those four years of keeping her alive to have been for nothing – well, somebody's got to pay. And since I can't make Jack pay, I'll go after her torturers. I don't like people who pick on the innocent, even if it's stretching things a bit to describe Ellini in that way."

Alice, still averting her eyes, had to judge this speech by the way it sounded. The woman had a whiny but honourable cadence. She was probably telling the truth. 

Well, it was a start. Not an ideal assistant – such as Alice herself had been – but a capable pair of hands that was not too vicious. She could work with it.

Yes, there was something here. An entire world of nonsense that needed her help, a bloody revenge to be prevented, centuries of illogical thinking to unpick. She could be useful here. And, who knew, perhaps she could even find the woman with the power to kill Jack? She would instruct the poor girl not to do it, obviously, but there was no harm in letting him think, for a moment or two, that his continued existence was entirely a matter of her discretion.

She dusted her hands and turned her attention to the matter of navigation. The cavern they were standing in was a sort of cross-roads. Six different tunnels branched off it, but only one of them had steam venting through the cracks in the rock. It had to be moving from the warmer to the cooler regions so, if they followed it backwards, perhaps it would lead them into the fire-mines.

She didn't bother to explain this to Val, who would only have thought she could manage on her own if she knew the way. Instead, she set out purposefully and left the woman to follow.

Along the way, she paid attention to her surroundings, in case they should prove useful. It was alive down here. Somehow, bats found a way in and out, and pale, majestic clumps of fungi rose out of the guano they left behind. There were also white spiders and scorpions – everything living, she supposed, on the mounds of guano left by the bats.

There were spindly white plants which gave off a sickly luminescence – a sort of corpse-glow. And then there were the gems. They too seemed to generate their own light. And some of them were faceted, as though a jeweller had already been at work, cutting and cleaning them, before they'd even been extracted from the rockface. Alice used Val's dagger to prise some out of the cave wall. She would present them to a geologist back at Oxford and see what he made of them.

What she didn't see was the man sitting back against the cavern wall. The white scorpions crawled over him as if he was just another outcrop of rock. Spiders spun webs between his splayed fingers. He opened his mouth, but that was so slow and organic as to be almost unnoticeable. The sound of his voice was like the steady drip of the stalactites, or the sigh of escaping steam.

It sounded like 'starwin' at first – only the 's' was unnervingly sibilant, and the 'a' absurdly drawn out, almost to the length of a gargle. Ssssstaaaaaarwin. Ssssssstaaaaarwin.

In another time and place, Alice might have wondered what a 'starwin' was. If she'd had to guess – which she would have done without a trace of uncertainty in her voice – she would have said it was a quaint Scottish dialect word for a baby star. But the odd, amplifying sound-quality of the caves allowed her to catch the first two syllables, which were breathed rather than voiced: 

A-li-sssssssssstaaaaarwin.

Someone down here knew her name.

And he was not sneaking up behind her like a thief, or lying in wait for her behind the next bend in the tunnel. He was the cavern wall she'd been looking at all along. Before her eyes, the rockface became a human face, veins of quartz became human veins. The bleak, bony projections of rock were suddenly bleak, rocky projections of bone: cheekbones and a clavicle, and ribs jutting out over a concave stomach.

And... Alice told her eyes not to travel any lower, but she couldn't help it. Of course, she was a married woman, so she had seen all this before, but unfortunately, it was much more impressive this time around.

The man – for man he certainly was – had a full, matted beard of white tinged with sulphurous yellow, like some bulging-eyed alchemist. He wasn't completely naked. A cloak was fastened at his throat, but it was open at the front, and it was either tattered beyond repair, or it had originally been made of fair, wispy hairs, because it hung in gauzy shreds down his back, like an echo of his beard.

And when he spoke, he spoke in iambic pentameter, which gave his words a strange, uncanny rhythm, like hoofbeats:

"I sought her not but she did come to me,

The dame who sent her lord into hell's fire.

With overflowing bosom and fair face,

Whose voice can bring about her heart's desire."

It took Val a moment to work out what was going on – Alice could practically hear the cogs in her thick head turning – but now she swung her sword at the man, stopping just short of his throat. "Who are you?" she growled.

"Quite unnecessary, thank you," said Alice, placing a restraining hand on her wrist. "Who are you, sir?" She wanted to add 'And how do you know so much about me?' but she didn't want to admit the accuracy of his description, especially the part about the 'overflowing bosom'.

The man's mouth split into a smile. "The one who played confessor to your Lord, without much understanding what he said."

"Can you speak in any other metres?" said Alice waspishly.

"Yea, lady, many others. In the hexameters of the ancients, if thou lik'st."

"I do not lik'st," said Alice. "Plain, unambiguous speech is all that will be required. And let me be equally plain: I do not have 'a Lord'. Certainly not one who would make confession to the likes of you."

"Needs must as the devil drives, my lady. And oh, how swiftly drives the devil here!"

Alice didn't shudder or glance over her shoulder, though she was clearly supposed to. "Kindly be more specific," she said.

The old man tilted his head. "Do not you know me, Alice Darwin? I set thee at thy post. And thou hast done thy duty like the fiercest watchdog. Thy counterpart, Oxford's other guardian, hath not such a fair face, but is twenty times more yielding."

"Why are we listening to this rubbish?" said Val, hoisting up her sword again.

"Because cutting people's heads off is impolite," said Alice, without turning to look at her.

"He's probably with those bloody gargoyles, he looks like the type. Didn't Jack say there was an old man with them?"

"That particular old man really did have his head cut off. Unless he has a very strong adhesive, I doubt this is the same one."

The old man sighed, as though, for the first time, he'd lost interest in terrifying and bewildering them. "Wilt come with me, good ladies both? I'll render thee fair answer."

"Ask him about the girl at least," Val prompted. "That is why we're here, isn't it?"

Alice rolled her eyes and turned back to the old man. "We're looking for a young woman named Mathilde Marron."

He shrugged. "I know her not."

"What about the gargoyles?" said Val. "Big, grey creatures with wings who enslave women."

The man regarded her calmly. "Of all demons can I give thee intelligence, for I know the fate of their Queen."

With that, he turned around and walked off down the nearest tunnel, leaving them to follow if they would. The cloak didn't do much to cover his behind, so Alice allowed him to get quite a long head-start before going after him.

Val followed, dragging her sword sulkily over the rocks and making as much noise as she could. "Why are we following him? Why won't you let me chop his head off?" she complained, as they picked their way through the tunnels.

"Is it honourable to decapitate an octogenarian?" said Alice. She had lost Val there – which, of course, was what she'd intended – so she rephrased. "He's just an old man. An impertinent old man, certainly, but no danger to either of us."

"I don't like the way he talks," said Val. "What century is he from, anyway?"

"I suppose he wants us to believe he's from the sixteenth or seventeenth."

"You don't think so?"

Alice just gave her a withering look. 

"He's pretty old!" Val protested. 

"Nobody gets that old."

"I feel as though anything could happen down here."

Alice didn't answer. She didn't want Val to know it, but she was uneasy. She most emphatically did not believe that this man had 'placed her at her post', whatever that meant, or that he had played confessor to her husband, but – well, she had told her husband to go to hell, and he had been an excellent walker. If he'd tried to follow her command, he could have ended up in a place like this.

She wasn't sure how she felt about the implication that her husband might be alive. James – or James Wesley Merriman Darwin, as he had sometimes insisted on being called – had been so touchingly dependent on her. In the Rhodesian jungle, he had taught cricket to the natives. Whenever his pay arrived, he had sent money to the 'old alma mater', and slightly more to the 'regular mater', whose name was Winnifred. He had called Alice 'old girl', and held the door open for her when they went out. None of this had been particularly clever behaviour, but she hadn't had the heart to condemn it in him the way she would have in other people.

The old man led them to a cave that was conical in shape. The ceiling stretched up for fifty feet, but it narrowed as it climbed, until the very top was about the size of a large coin. And, as if to facilitate this analogy, it was silver – or rather, silver poured down from it. She was staring at it for a while before she realized it must have been moonlight, filtering down from an opening high above them. They were standing at the bottom of a deep, deep well.

She also realized that the old man was a collector of all the rubbish thrown down here from the world above. Crumpled newspapers had been painstakingly smoothed out and mounted on the walls. A little shelf had been carved out of the rock for displaying coins, as though they were small, decorative plates. Broken clocks, all displaying different times, were ranged in alcoves in the walls. One of them had moss – or some other damp, greenish growth – creeping halfway across its face.

"Have you been living here long?" she asked, trying not to breathe too deeply.

"Three score years," said the old man. "Times five."

"Three hundred years?"

"Thou hast a quick mind, Alice Darwin."

Val snorted. "You couldn't possibly have lived for three hundred years."

"Nay, good Amazonian. Three hundred years is but the length of time I have spent here. My life hath 'dured above three hundred and fifty."

"You mentioned my husband," said Alice, keeping her voice determinedly light and scornful. "Is he here?"

"Nay, he wanders on, searching for a place to which he cannot gain admittance while he live, and may not gain admittance when he die."

Alice didn't rise to this. None of his spooky, circumstantial arguments were going to convince her that he'd seen James. She would wait for evidence.

"So you live here all alone?"

"But for the jades in the stables," said the old man, motioning to a rough, window-shaped hole in the cavern wall.

Alice was about to protest that it was barbarically cruel to keep horses down here, when she heard Val gasp, and went to join her at the window. It looked through into a much larger cave, lit once again with the dim glow of those tube-like, phosphorescent plants. There was silver in here too – more erratic than the steady moonlight, more the sort of silver you'd see from a startled fish in a pool – but it was a while before Alice could pinpoint its source.

Val realized what they were looking at first, and said, in her grumbling, obvious way, "Are those dragons?"

Alice understood now why the Anglo-Saxon word for dragon had been 'wyrm'. They were worm-like, yet without the negative, meagre connotations of that word. They were like slim, silvery strips of cloth, undulating in the breeze.

She was stunned. And the frustrating thing was, there was no reason why she should have been. She had seen dragons at the Zoological Gardens. The Principal of Magdalen even kept a small one in the college vaults. She had studied demon bones and new-breed physiology, and knew all the fantastical permutations of both. And yet, somehow, these dragons – graceful beyond physics – were more than she'd expected. They lent legitimacy to the old man's claims that he was three hundred and fifty years old, and had spoken to her husband. She couldn't think of anything scornful or practical to say. Val was standing beside her, open-mouthed, waiting for her to take charge – probably ready to start swinging that sword about if she didn't – and she had nothing to say.

"Achillea Bonnesatva," said the old man, behind her. "Or Messenger Dragons. Yet have they never seen fit to share their message with me. But eleven years have I known them – before which time, I had only the spiders. Yet, the spiders being incapable of speech, their silence was no slight to me."

Alice didn't take her eyes off the dragons. "Your name, sir?" she managed faintly. 

Perhaps he had been waiting for a hint of weakness from her, because his smile was slightly kinder now – although still just as yellow.

"Johannus Faustus," he said. "He who sold his soul to the devil – of which you shall hear more hereafter. Presently, I mean to speak of one who is not unknown to you, whose life doth run in circles like the spider's web, yet whose wand'rings are ever converging on a centre. When thou understand'st the nature of her life, thou wilt understand my purpose. I sold my soul to gain knowledge of it, yet for three hundred and fifty years have had none whom I might teach. Conceive of it, Alice Darwin. Such might be deemed hell for you as well as I."