It was funny how you could have a conversation like that, and feel all the despair melting away in a moment. And it was funny how swiftly and inexorably it crept back.

All the things he had felt when he'd been talking to Elliott – about the beauty of Franconia, the healing power of the boy's music, the way he himself could never have Ellini, because he was a murderer and nothing could ever put that right – she had made a mockery of it in a moment, with her smiles and kisses and quick answers.

But still – still – it waited for its opportunity and crawled blackly up his spine. It was the piano, perhaps. For some reason he couldn't quite put his finger on, it reminded him that he was a killer.

He was looking at it now, in the hallway of the Faculty. It had been installed in the shadow of the great oak staircase, and was, to Jack, no less dark and portentous.

Elsie had run her busy fingers over it as soon as she'd come in. And even now that tea was served, she hovered beside it with her cup and saucer in one hand, occasionally pressing a key in a way that set Jack's teeth on edge.

"It's exactly the one I saw," she said, as E minor died away into silence. "You're a third of the way there already."

"I just have to own the piano?" he asked. "I don't have to do anything with it?"

Elsie shrugged. "Haven't the faintest idea what you have to do with any of the objects. I just know you have to collect them."

Jack passed a hand over his eyes and tried to unclench his jaw. Elsie had arrived about an hour ago, and had greeted him with the ominous question: "Are you happy? In yourself?"

When he had returned a dubious "Yes?" she had tilted her head, as if wondering whether this would do. Then she had seemed to scent the piano, and had gone off to pat it down as though it were a lovely horse.

Danvers had been in tow, of course. And Sergei had soon come down, because it turned out that Elsie had come to see him a lot during the months when Jack had been in his own private hell of guilt and grief. 

Sergei seemed to treat her as a favourite niece, always keeping some little sweetmeat at hand for her visits – comfits, peppermints, candied fruit, sugared violets. This afternoon he greeted her with a bag of aniseed humbugs, and ordered Sarah to fetch some tea, which they took in the hall due to the sheer impossibility of dislodging Elsie from the piano.

"What about the ring?" Jack prompted, watching the surface of his tea quake as those perfectly-tuned notes rang through the hall. "It was the ring, wasn't it? The one she threw into the demon realms."

"I can't help you find that," said Elsie. It seemed like a response she had been practising for some time.

"I know you can't help me find it, I just want to know whether that is the ring I have to find."

Elsie seemed to think that even this was a betrayal of Ellini's trust. She started to nod, but then thought better of it, and jabbed restlessly at the piano with her fingers.

Jack shuddered, but didn't shout. It was answer enough, after all – not that he had really needed her confirmation. He had known as soon as he'd heard the splash. He had watched it in his mind's eye, sinking to the bottom of that otherworldly lake, into the silt and seaweed.

He couldn't find it – not without Elsie's help, not before Ellini left for Edinburgh. Would two of the three items be enough? Of course not. It was bloody magic. Magic couldn't stand half-measures – or even two-thirds measures.

Perhaps Elsie had been following this train of thought, because she gave him an infuriating smile, patted his arm, and said, "Best to take it one step at a time. I can get you to the level of hell where Sita is, and that's quite enough to be getting on with. I can't go myself, I think, because the items have to be collected by the right person."

"What I am worried about," said Jack, forcing himself to stop staring at the agitated surface of his tea and just drink it, "is the time difference. If I'm down there for, say, an hour, how long will I have been away when I get back here? If the past twenty years have been like twenty minutes to Sita-"

"I didn't say that," Elsie countered. "That was your guess, not mine. It's hard to tell how much time has passed for Sita, because she's been falling through lots of different time-zones. That's one of the reasons I had so much trouble locating her. Now she's come to rest, I can be a bit more accurate. One hour on this level of hell is equivalent to about a week up here."

"A week," said Jack, in a flat, toneless voice.

Elsie nodded. "So my advice is, don't spend longer than an hour down there."

"Will she be easy to find? Will I – appear – quite close to her?"

"No and yes. That is, you'll materialize close to her, but nothing will be what it seems down there, so she might be hard to recognize. Have you heard it said that magic and humanity don't mix?"

"I never thought I had much humanity anyway," Jack muttered.

"You have enough for it to complicate matters. Sita, too, if she's conscious. The space around you both will sort of – mould itself to your thoughts. The demons you meet will look like people from your memories. It will be a bit like a dream, I think. That's why I asked you just now whether you were happy in yourself. Historically, visitors to the underworld have fared better if they don't know the meaning of self-doubt – you know, like Hercules and Odysseus. You sort of... get what you expect, in the underworld."

Jack sunk his head in his hands. "Oh god."

Well, he was a confident person. Everybody said he was. And he was forever being compared – not always flatteringly – to Odysseus. He knew how to stop thinking in the heat of battle and just believe. He could talk almost anyone into compliance. It was just that his enemies, previous to this, had not been able to see inside his head.

"Am I to understand that there will be an open door to the demon realms in my hallway for a week?" said Sergei. "If so, I think some kind of screen or curtain might be in order, to stop the students wandering in."

He was being infuriatingly cheerful about the whole enterprise. This was possibly because his son had gone to London, Ellini had removed her distracting presence from his house, and Jack cared about something again. Somehow, this combination of circumstances left Sergei free to be his sprightly, sarcastic self. 

"Will anything wander out?" he added, as he sipped his tea.

"Oh no," said Elsie. "They won't come until they're called – that is, by me."

"Will you spend the week here?" asked the doctor. "Mr Danvers could have his old room, as I daresay he would object to being parted from you."

Danvers spluttered his thanks until Jack got impatient and cut across him. "How cosy you're all going to be while I'm risking my neck in the underworld."

Sergei replaced his cup in his saucer and started up, as if he'd just remembered something. "As to that, I have a present for you. Do excuse me, Elsie. And it isn't the underworld, Jack. You won't be meeting the dead, just another type of the living."

He disappeared up the staircase, and returned a few minutes later with one of the sharpest, spikiest specimens of the Jigsaw Room. It was an axe. There was probably a technical name for the shape of its blade, but the best Jack could think of was 'droopy'. It slanted down at a sharp angle, and then tapered to a point. It was like the profile of a man with a very long, hooked nose.

One of Jack's little chores in the days when Alice had been his keeper had been to polish the weapons in the Jigsaw Room, and he had often given this one a few wild, experimental swings when he had thought nobody was looking.

It turned out that Sergei had been looking, because he said, "I noticed you admiring this during your time with us. As ever, I think you misunderstood its purpose. It seems to have been used primarily as a mining implement, rather than a weapon. The shape of the blade is consistent with those of axes that have been found in Boeotia for clearing tree-roots in subterranean spaces, and the pick on the back has been extensively used, perhaps for climbing up sheer rock-faces, or clearing passageways after a cave-in."

"Oh, that's disappointing," said Jack, looking wistfully at the axe.

"I daresay it would work just as effectively as a weapon," said Sergei. "Only I thought you might have been hesitant to harm any of Elsie's kin. Particularly after your promise to Miss Syal?"

"Oh, they'll be trying to kill you," said Elsie in an offhand way. She was fidgeting by Sergei's elbow, anxious to run her hands over the axe.

"Please be careful, Elsie," said Danvers, hovering just as restlessly at her elbow. "It looks devilishly sharp."

"Why will they be trying to kill me?" said Jack, annoyed that this point had been so unceremoniously uttered and so easily dismissed.

Elsie had got hold of the axe now, and was running her hands over the blade. "Oh yes," she breathed. "I know this. It's a tool, but a magical one. Made to make the trees shrink back and the rocks melt away. You see these markings on the handle?" She pointed out a column of raised symbols, sharp and angular, like runes. "It's writing. It invokes the primordial Goddess – that is to say, me," she added, with a little, embarrassed smile. "It says 'In the name of she whose voice has made rocks to weep, and softened stony bosoms, turn aside, adamant, and be humble'."

The silence that followed was broken by Sergei heaving a sigh. "My dear Elsie, might I trouble you to look at all the specimens in my collection? Perhaps we could spend the week annotating the exhibition catalogue?"

"Lovely," said Jack, with real bitterness now. "When the demons tear my head off, it will be a comfort, I'm sure, to know that Sergei will have a well-annotated catalogue."

"They'll only be trying to kill you because you're an outsider," said Elsie. "They'll be defending their territory. Anyway, I can't predict how your presence is going to warp the place and the people. If your mind isn't hostile to you, perhaps the surroundings won't be either. Although, if Sita's mind is hostile to her – or hostile to you – that might not matter."

"Oh lord," said Jack, raking a hand through his hair. 

Perhaps Sergei was touched by the plaintive note in his voice, because he offered to take Jack upstairs and make a kind of holster for the axe, so that he could use both his hands for climbing, or pleading, or whatever it was he intended to do. 

Jack disregarded the sarcasm and took the help. They ended up twisting a strip of leather round his shoulders in a figure-eight, so that he could tuck the axe into the place where the leather crisscrossed and wear it like a backpack.

"Since the issue of a demonic dress-code will probably not be raised," said Sergei, "and since hell is proverbially hot, I think you might do without the jacket and neck-tie."

Jack stripped down to his waistcoat and shirt-sleeves, re-tied the holster, and then hefted the axe experimentally. Oh, it was a beautiful thing.

He squinted at his reflection in the blade and wondered whether he was looking forward to this. In a way, he was excited. Descending into hell, brandishing an axe, rescuing a little girl – it was straight-forward, the sort of thing he'd been trained to do. It was unlikely to involve any tact or soul-searching. Hadn't he been waiting for an opportunity like this? To be useful to Ellini in a way that came easily to him?

Except it wouldn't be easy. He would be facing his own mind and his own memories, and he wasn't allowed to kill anybody. And he would only have an hour.

He felt as though he was waiting to come alive. A challenge like this usually quickened his pulse and kindled sparks in his brain, but, at the moment, he was just staring at his reflection, desperately searching for something he recognized.

It would come at the crucial moment, he decided. It always did.

"Is this an antique?" he asked, letting his focus slide from the blade to Sergei's inscrutable face.

"In fact, it is an antiquity," said Sergei.

"Are you sure you want to give it to me?"

Sergei gently took it from him, and slid it into the leather straps that crisscrossed his back. "Bring the girl home. I have lots of antiquities."

Jack left Sergei rearranging the exhibits in the Jigsaw Room, trying to hide the blank space where the axe had hung on the wall. Giving it away was probably more of a wrench than he was letting on, but Jack couldn't argue with him, because he understood the motivation. Sergei's head was apparently not resounding to the strains of Rule Britannia, or its North Dobrujan equivalent. Sergei, it seemed, was for real.

He paused on the staircase, treading by habit on the secret spots he had memorized long ago, which never betrayed a creak. Elsie and Danvers were in the hall beneath him, arguing. At least, Danvers was arguing. Elsie couldn't seem to decide what was happening. She couldn't understand why Danvers had withdrawn his hand from hers, or turned his back. She kept walking round to try and get in front of him, and he kept turning from her.

"All this talk," he was saying, "makes me realize how very far apart we are."

"What do you mean?" said Elsie, half-laughing. "We're right here, both of us."

"But we're from different worlds. And I know nothing about yours."

She reached up to touch his shoulder, still smiling bemusedly. "Well, think how little I knew about your world when I first came here. I didn't know where the water in the taps came from, or why women should wear corsetry. It's amazing what can be achieved by a little talking."

Danvers turned a stony, stoic face on her. "Elsie, in this case, a little talking is not going to be sufficient."

"A lot of talking, then?"

He sighed, and dropped his hands, and started pacing about in agitation. "When will you want to go back home? Be with your own people?"

"But I am with my own people," said Elsie. "I'm always with them, just like I'm always with you – only it's harder, being with you, because I have to do it physically – you know, by following you around, and holding your hand, and-"

"It is not disagreeably hard, I hope?" said Danvers, in a voice as cold as Danvers knew how to make it, which wasn't very much.

Elsie was too bewildered to answer, and Jack's hand wrung the banisters in exasperation. God, he was so dense! Didn't he understand that 'disagreeably hard' was a contradiction in terms for her? If something was hard then it was a challenge, and challenges made her come alive. They made her demon-world more beautiful.

But no, Danvers had to be so English – so blindly noble and self-sacrificing. 'This is how things are, and so our love can never be'. It made him want to scream.

"We're from different worlds," said Danvers, "and it isn't proper-"

Suddenly, Jack couldn't bear it. He had been preparing himself to bear it, and then he had heard the word 'proper', and that was it. That was the crucial moment. Who knew what he would do when another one came along, but for now he was Jack, and Jack fought bloody-minded English propriety with every trick at his disposal. That was who he was and what he was supposed to do. One step at a time.

"Danvers," he said, hurrying down the stairs in a flurry of creaks. "I was just thinking about that book you lent me on W.G. Grace. The thing that impressed me most about him – apart from the big, bushy beard, of course – was the way he stayed on top of the game even when the sport of cricket was changing beyond all recognition. I mean, two years after the legalisation of over-arm bowling, he was batting an innings of 244 not-out for All-England against Surrey at The Oval, as if he'd never known anything else. That's real heroism, if you want my opinion. Staying afloat no matter what life throws at you, adapting yourself to each new circumstance for love – in W.G.'s case, the love of the game. That's the true career of the gentleman."

He beamed innocently, while Danvers struggled to find the words to commend this unprecedented interest in – and knowledge of – cricket.

Would he take the point? Jack didn't feel as though he had been particularly subtle, but there was nothing in the world more self-deluded than an Englishman. Elsie had taken the point, perhaps, because she was looking thoughtful – tilting her head again as if the air was whispering prompts. Was she beginning to suspect now that Danvers was in love with her? God, what wouldn't Jack give to stay and watch that play out?

Well, he wouldn't give Sita, obviously. And bearing in mind how infuriating Danvers could be – especially when he was happy – Jack thought it would be no bad thing to spend some time in a completely different dimension.