For a long time after Jack left, Ellini sat rigid on the floor of her bedroom, feeling the blood rise in her cheeks and the heat creep into her hair.

Half of her was pleading with herself not to get excited—not to believe Jack when he said he'd give up Alice Darwin, not to entertain the idea that perhaps things were going to be all right—because, once she believed all that, there would be a terribly long way to fall if she was proved wrong.

But she couldn't help it. Her heart was pounding in her ears. Her hair was getting so hot it was practically smoking.

He liked her just for her—not for any advantage or gratification he could get. Just for her mind and her company!

Why hadn't she understood before how romantic that was? He willingly sought her out and chose to be with her when he couldn't hope to gain anything from it. Lust didn't lure him towards Alice Darwin as often as camaraderie drew him towards Ellini.

There were lots of things that still weighed on her, though—nauseous spasms of guilt when she thought about Mr Danvers, and cold shivers of dread when she thought about Alice. And waking up every day with the memory of the fire mines... it would be so much work to come to terms with. She had been putting off thinking about it, in the expectation that she'd be dead soon, but if she was planning on staying alive, there would be so many hurdles. She'd be bound to fall at some of them.

Could Jack really pull her out of all those dark moods? A Jack whose eyes would always be wandering? A Jack who said things like: 'Let's be honest, you're not exactly a girl who wears her attractiveness on her sleeve'?

There would be no more distractions—only kind people, and the shadow of self-worth that she had managed to secure through being Charlotte Grey. How could that possibly be enough? God, she was so frightened—so frightened of the moment when that blackness opened up before her, and all her dead family-members called her down into the abyss.

But, at the same time, she was so excited. Everything seemed possible now—even kissing him and breaking the spell and getting him back.

It was a stupid, impractical idea, of course. If she kissed him, he would try to fight the gargoyles, and then he would be killed. But her mind couldn't help going back to it, as though it had missed something—as though a solution would present itself if she looked hard enough.

She wandered through the Faculty in this state of happy agitation—up and downstairs, in and out of laboratories and apartments, without really seeing any of it. She ended up in the Jigsaw Room, although she didn't realize it until Dr Petrescu came in, carrying a large, flat box that was tied up with green ribbon. Ellini snatched the ruby-studded comb out of her hair guiltily.

"Jack said I could—"

Sergei waved a hand. He was busy putting his box down on one of the glass cases of demon artefacts.

"Would you feel better about it if I told you we've recently discovered it's a fake? It's a very good fake. Made by one of the best art forgers in London, and probably worth a few pounds on that basis alone. But it never belonged to a demon, as a comb or a knuckle-duster. It certainly never belonged to—" He hesitated and raised his eyebrows. "What was it? The demon queen Jalfrezi?"

Ellini gave a nervous laugh. She was afraid he would see the fluttering marks of elation that Jack's visit had left on her. And yet she didn't know how to go about slowing her heartbeat or getting the blood to sink out of her cheeks.

She didn't want to hurt Dr Petrescu. She had grown to respect him—even to enjoy his conversation—during her stay at the Faculty, although it made her head swim with guilt, because she could see what she was doing to him.

But he was so gentle about it. He never stared or got too close. His attraction to her seemed to make him sad rather than desperate. She wished everyone who fell in love with her could take it that way.

"Have you been shopping?" she asked, nodding towards the flat box. "Is it another demon artefact?"

He smiled and frowned at the same time, as though he was about to embark on a lengthy academic explanation. "No, it's—well, it's whatever you want it to be, really. Jack told me he was going to ask you to marry him."

Ellini's face fell, and the blood sank out of her cheeks of its own accord.

"I would like you to consider it," Sergei went on.

"Consider—?"

"Consider marrying him. It's not as impossible an idea as it might seem. He is right in thinking that Alice would never contemplate throwing him out. He represents years of research. If he were to tell her he'd only stay if he could marry you, she would allow it. And I am working on getting Danvers back," he added, with a little less assurance. "It's just—they never really got along to begin with..."

"I don't understand," said Ellini, trying to suppress an urge to run in panic from the room. "You want me to marry Jack?"

"You would like to understand?" said Sergei, as though this was a nice surprise. "The explanation might be a bit involved, and I'm never sure how much you enjoy these little lectures of mine..."

"Of course I enjoy them."

"Of course," he chuckled. "'Of course', she says, with that solemn, inscrutable expression—as though it's obvious."

"I don't—"

"My fault. I'm getting side-tracked." He sank into a carved stone chair that Ellini had always assumed to be one of the artefacts. She could see the rusted remnant of chains poking out of its arms. "I wonder, what do you think I did for a living before I came to Oxford?"

"You mean back in Tomis—uh—Constanța? Weren't you a doctor?"

He tilted his head. "In a sense, I was. But I only had one ailment to diagnose. I examined my patients for demonic symptoms. If I found them to be new-breeds, I signed the papers certifying their inhumanity and handed them over to the witch-guards to await deportation to the prison colonies."

Ellini felt a chill against her glowing cheeks, but she kept her head up. She didn't want him to see her flinch away, even though he had just confessed to earning a living by deporting her kind to death-camps.

"You were a—a witch-finder?" she asked.

She had heard of them. In Britain, new-breeds were technically only deported to the prison colonies if they'd committed a crime, but in other countries, they were deported by default. Just for having the temerity to exist.

A whole science had sprung up around the process of identifying them. The witch-finders measured their fingernails, examined their scalps, timed their reflexes, and took their temperatures. They didn't get involved in the messy business of chains and human cargo, but they were part of the process. They must have known.

Perhaps Sergei guessed her train of thought because it took him a moment to answer her. He was toying with the arms of the stone chair, picking at the chains embedded in the stonework. When he spoke again, it was almost his usual, genial voice, but there was something constrained about it. It had lost some of the Sergei sparkle.

"I was born into the profession, really. My father was a witch-finder. He died of scarlet fever when I was ten, leaving me to be the sole breadwinner for my mother and sisters. When one of his colleagues offered to take me on as an apprentice and train me up to identify new-breeds, I thought nothing of it."

He stopped and looked up at her—or rather, two inches to the left of her, because he was too considerate to stare. There was a rueful smile behind his moustache.

"I'm not going to try and justify myself to you. I didn't know about the appalling conditions in the prison colonies, but the truth is, I didn't ask. I didn't want to know. I'm not like Jack, you see. I never had his—" he sucked in a breath through his teeth, as if searching for the right word. "—his lucky arrogance. I never thought I could change the world."

He drummed his fingers on the arm of the chair, half-frowning, as if he was annoyed with himself for getting side-tracked.

"There was one thing that comforted me, whenever I started to wonder what happened to my patients when they left my door, and that was the fact that I had never made a mistake. I'd never sent a human to the colonies, or spared a new-breed because they offered me a bribe. I'm not sure why I thought that was something to be proud of. I suppose, if you stick to the rules carefully enough, you can blame the rules for your actions, rather than yourself."

He smiled thinly. "At any rate, I did break my rule once. It was my last week in the job. My sisters were married and settled, I had a place at an Oxford college, I had already handed in my resignation papers. And that was when the witch-guards delivered Elisabetta to my door. They said she could make herself insubstantial—a fairly common demonic symptom among the new-breeds of Eastern Europe. They said they'd seen her walking through solid walls to get away from them."

Ellini sank down on the rug and drew her knees up to her chest, lost in the story. She had forgotten about comforting him or trying not to look disgusted. She just wanted to hear what happened next.

"She was obviously a new-breed," Sergei went on. "She sank half an inch into the table when I asked her to sit on it. But I carried out my checks anyway because I had rules to follow. She asked me—in a deadened voice which suggested she had no hope of my compliance—not to tell the witch-guards what she was. She said I could have anything I wanted from her. Anything."

He smiled and scratched his moustache, as if he was amused by his own frankness. "I, in typical scholarly fashion, told her I didn't need a concubine. I needed a secretary."

Ellini's breath caught in her throat. It was half a laugh and half a sigh. She could just imagine Sergei—a young Sergei, but still inescapably Sergei—saying something like that to a woman he was hoping to impress.

He went on as if he hadn't heard her exclamation, still smiling in his rueful-but-cheerful way. "I said if she would file my papers, post my letters, that kind of thing, I would take her with me to Oxford, where new-breed rights have been respected for three hundred years. It was like offering her a ticket to the Elysian fields. Oh, she was sceptical—understandably sceptical—but you should have seen her eyes light up. For that brief flicker of a second, she came alive."

He broke off and frowned again. Ellini was starting to recognize the expression. He wanted this to be like an academic lecture—he wanted to be mild, dispassionate, and informative—but the subject was too raw, even now. It wasn't just the guilt. These memories must have made him happy as much as they made him cringe.

"I don't know why I did it," he went on, in a voice that was struggling for steadiness, "why I broke the only rule that had ever made me feel good about my job—the fact that I'd never made a mistake. Elisabetta was pretty, but I'd seen prettier women. I sent them all away in chains."

His voice faltered, and he seemed to become very interested in the chair-arms again.

"At any rate, I signed the papers certifying her humanity. I brought the guards back in, told them to unlock her chains, and launched into an impromptu lecture about optics, and how the vagaries of fading light could make people seem to pass through solid objects. I remember that very clearly because terror was sharpening all my senses. I'd never done anything that reckless before."

"I found Elisabetta lodgings in a very respectable boarding house for young women. I think I wanted to prove to myself that I had no intention of taking advantage of her. It was above a bakery, so she always turned up for work with her skirts trailing the scent of pastry and almonds."

He took a deep breath through his nose, as if he could still smell it. "Then I began training her as my secretary. That was very enjoyable, because it gave me free rein to talk about my research and my readings. She listened attentively, but I could never tell whether she was interested, amused, or just bored. I suppose she had got into the habit of keeping everything on the inside. From the little I could discover about her life before Constanța, she had been running from the age of five."

"Anyway, she watched me with her dark, inscrutable eyes while I rambled on about Hamlet, or the second law of Thermodynamics. We sat on the sand dunes outside the city and watched the steamers pull out of the harbour, laden with a human cargo that I was no longer responsible for putting there. I was happier than I'd ever been in my life."

Ellini stared at the pattern of fibres on the rug beneath her. Sergei's voice was steady—this memory had probably been revisited so often that it had lost its power to upset him—but her chest still ached with sympathy. She couldn't have met his eyes.

He cleared his throat and went on. "The night before we were due to leave for Oxford, she left the boarding house—God knows how, because the girls were guarded like bank vaults at Madam Antonescu's place—and came to my lodgings. I don't know what made her do it. Perhaps she felt grateful to me, and she didn't know how else to show it. Perhaps she genuinely found me attractive—this was nearly twenty years ago, you understand, and I wasn't quite as old and crusty as I am now. Anyway, I didn't protest. I was a nice, respectable man, but I wasn't dead."

Ellini smiled sheepishly, still keeping her eyes fixed on the rug.

"The morning after, amid the chaos of carriages and packing cases, I told her I'd apply for a marriage license as soon as we got to Oxford. She was skeptical again—I think she had learned to take the promises of men with a pinch of salt—but she agreed."

Sergei sighed, and when he spoke again, there was an edge to his voice that made her suspect the story was approaching its end, whether he liked it or not.

"I could feel Elisabetta getting more and more nervous as we approached the border control at Bucharest. She kept sinking into the seat of the carriage without realizing it. I told her she had genuine papers certifying her humanity, signed by the best witch-finder in Constanța, but she continued to be pale and silent."

"Still, I was impressed by her composure when we reached the border. She climbed out of the carriage quite steadily and stood beside the lowered barrier blocking the road while the border-guard inspected our papers. I was already planning the way I would congratulate her on the train, when the guard handed back our papers and waved us on. She was so relieved that she walked right through the lowered barrier."