Where did you start looking for a woman who had disappeared from the scene of her own murder? 

It was a paradox that Elliott had been struggling with for days. There was a corpse in the mortuary. She had been sketched and photographed, and presumably examined by the coroner. Any day now, perhaps, she would be buried.

And she looked exactly like the beautiful woman whose eyes had met Elliott's when he'd thrown back the curtains of the main recital room. The woman who had smiled and touched a finger to her lips and disappeared before he could question her.

But it wasn't her. It was some kind of copy. He didn't understand how it had been made, or why it was necessary, but he knew he needed to find the real woman. He had never felt such an affinity with anyone.

It wasn't that he thought he'd met her before, in some forgotten moment, or even some other life. He just knew that, from the one glance they'd shared, he had understood everything about her. And she had felt the same – he knew it. He had seen her look of shock melt into a smile, as though she'd just been met by an old friend.

But why had she run? Well, she was in danger, clearly – why else would you fake your own death? But why hadn't she trusted him to help her? If she had understood him in that moment as completely as he'd understood her, she would have known there was no need to run.

Still, the frustration was doing him some good. It hadn't occurred to him to despair after that, even though, in many respects, his predicament was actually worse. Now he was in love with a woman he had only seen once, who he had no idea how to find, and who, by all the evidence – except the evidence of his own eyes – seemed to be dead.

And yet he was finally certain of something. He finally knew what he was supposed to do. Three days after the murder, he even made himself walk out of the music rooms and into the heaving crowds of Broad Street, with no more than a twinge of anxiety and a half hour or so of sweaty palms.

He tried to remember the last time he had been outside – apart from the night he had darted wildly after the girl – but this just brought back memories of soirees and dinner parties and grand reception rooms. He supposed it was encouraging to think that none of the pedestrians on Broad Street were going to judge him by his skill with a fork, or his after-dinner conversation. No-one was going to ask him what he thought of the new Reform Bill, or the operettas of Sir Arthur Sullivan.

And so, feeling a little bit braver, he shuffled into Turl Street – with his hat standing in for the security of a ceiling – trying to re-find the last place he'd seen her.

Of course, it had been close to one in the morning when she had darted through these streets – and she'd been wearing a grey dress and keeping to the shadows – so it was unlikely that anyone would have seen her. And what could he say when he asked them? That he was looking for the dead girl? The one they'd all seen in the papers? The one whose murder was currently being investigated by the city police?

As it happened, this line of enquiry yielded surprisingly good results, but not for an hour or two.

He found himself in the covered market – which, at least, was covered, even though it was squirmingly close, and packed solid with human beings. 

Elliott asked for the man who guarded the market at night, only to be told that there wasn't one. But there was a superintendent who locked the gates after six, and sometimes wandered back to check that all was well on his way home from the pub. One trader even described him as 'an agitated little bugger who hardly sleeps', and said he wouldn't have been surprised to see him slinking around the aisles of the market at night.

This was Elliott's first piece of luck. His second was that the 'agitated little bugger' – a description which hardly did him justice – was something of an amateur detective. Better yet, he was clever, and desperate for other people to realize it, which made him extremely communicative.

His name was Jacob Rookwood, which had a pleasingly musical sound to Elliott. And sure enough, when he finally met the man – standing to attention at the Market Street entrance – he had a deep but whining voice which sounded very much like a double bass.

Elliott hadn't worked out what he was going to say, and was already starting to feel nauseous from the ever-present pressing of the crowd, so he settled for a vague, meandering honesty.

"I'm – uh- looking for someone who might have passed through Market Street on the night of the fourth of July," he said, squirming at how obtrusive and unnatural his American accent sounded in this place. "A very thin woman with dark hair, wearing a grey dress? This would have been at about one o'clock?"

He had definitely hit on something, because Mr Rookwood's eyes widened triumphantly before they narrowed again. "Hardly a decent hour for a woman to be out alone," he said.

"This woman was – well, to be perfectly frank, she was the one they found dead on the steps of the Turl Street Music Rooms," said Elliott helplessly. "Except, at the same time as they were finding her dead, she was also running through Market Street."

Mr Rookwood gave a dark chuckle. "Doesn't seem right, does it, sir?"

"I must admit, I don't understand it yet."

"S'perfectly logical if you only think for a bit."

But Elliott could have thought for two thousand years without coming to the conclusion that Mr Rookwood offered.

New-breeds could split themselves in two, he said. Like when you chop a worm in half and it becomes two separate worms. She knew she was dying, so she split herself in two, and left one half to perish on the street so that nobody would come looking for her.

"'Course, every time you do it, you lose a little bit of yer soul," said Mr Rookwood. "That's why you never see 'em doin' it. It's always an absolute last resort. Some'd rather die."

He hooked his thumbs in the pocket of his waistcoat and went on. "So I sees 'er that night, running through the streets, an' then I read about her death in the papers, at the spot she was running from, and it all makes sense. Well, that was that, I thought. No use tellin' the police – they're all idiots – and what business is it of mine if the poor girl wants everyone to think she's dead? But then my Janie takes a cab with 'er mistress, and tells me she saw blood on the seats. I figure the girl would've 'ad to get out of town. And at that time of night, a cab would've been the best way to do it. So I tracked down the cab my Janie took, an' asked the driver about it. It was Charlie Connor, who I've known from Adam – but I've never known 'im to be as cagey as this. Said 'e didn't remember any of 'is passengers that night. But I knew something was going on, 'cause I heard from 'is landlord that 'e was all paid up with the rent, and that never 'appens, 'cause Charlie's always a gambler first, an' a husband and father second. Someone gave 'im money, and made 'im think twice about throwing it away. And this new-breed gets to you – that's about the only thing anyone can agree on."

Elliott, trying to keep the excitement out of his voice, asked him where he could find Charlie Connor, but Mr Rookwood just gave a contemptuous shrug. "'E won't tell you anything. She was in trouble, an' 'e's got three daughters of 'is own. She brought out the paternal instincts in our Charlie. 'Course, 'e's always a gambler first, as I say. Maybe if you can make 'im feel like 'e stands to win something..."

Mr Rookwood trailed off, and then looked him up and down, as though wondering whether or not he was up to the job. "You're from America, aren't you?"

"Yes," said Elliott. He thought of adding that this was a little like asking an Englishman if he came from Europe, but dismissed the idea. At any rate, Mr Rookwood quickly made up for it by saying, "Which part?"

"New Hampshire."

Mr Rookwood gave a contemptuous shrug. "Well, it's got to be better than the old one. My brother went out to America last year. 'E keeps saying I should come and join 'im. Says it's nothing but pretty girls and wide open spaces."

Elliott tried to tuck in his elbows, as another stream of shoppers, porters and workmen barged past him. "Well, he's right about the open spaces, anyway."

Mr Rookwood told him to ask for Charlie Connor at the cab stand outside the Magistrates' Court. Elliott didn't know where this was, but was too eager to get out of the covered market to say so.

Once outside in the fresh air, he leaned against a wall in Turl Street, staring blurrily at the gargoyles above him, and took a few deep, steadying breaths.

He would not go back to his piano. He would find a policeman and ask him the way to the Magistrates' Court.

He didn't have a plan, or anything with which to bribe the reluctant Charlie Connor. It seemed too much to hope that he would be a music lover. But he had the certainty that this was something he was supposed to do, and it had already got him out of the music rooms, so there was no telling what else it could accomplish.

The policeman pointed him down St. Aldates – the most crowded of the four streets which branched off from Carfax Tower. Elliott had seen denser crowds in London, or Milan, but that had been from the comfort and seclusion of a carriage. Now he had to pick his way around the horses and barrows and donkey-carts, apologizing to people who either ignored him completely or gawped at his strange accent.

He was obviously drawing attention to himself, because he'd barely got two steps down this formidable street when a carriage screeched to a halt beside him, and Magda got down, in her impeccable grey walking suit and an ostrich-plumed hat. She looked every inch the Duchess, which was impressive, because she wasn't yet. Still, the wedding was only a week away, and she was the most determined person Elliott had ever met, so he supposed it was unavoidable now.

"Elliott," she said, taking his arm and dragging him out of the path of a street-sweeper. "Where have you been? I've been looking for you everywhere. Mr Gambosi has rearranged your concert dates. We'll be sailing for Paris a week from Friday."

She was accompanied by a lady in an even smarter dress, with the upright, overstuffed look of a large woman in a lot of expensive corsetry. She said "How do you do, Mr Blake?" in a tone that made Elliott's spirits plummet, because he was obviously supposed to know her, and she was indistinguishable from every other aristocrat he'd met in the past few weeks.

Still, he did his best. "It's – uh – Frances, isn't it?" He drew out the 'a', so that it sounded like 'Frahnces', the way the English insisted on pronouncing it, but even this was not enough for Magda.

"Lady Frances," she said, elbowing Elliott in the ribs, before turning back to her companion. "I'm so sorry, Frances-"

But the Lady held up a hand. "Please don't apologize, my dear. It's the artistic temperament. One can only encourage it if one wants to listen to great music."

Elliott thought of giving Magda a smug smile, but decided against it.

"We met at my house at Roehampton," Lady Frances went on, "at a little soiree I'd arranged for the Master of Balliol."

Elliott gave her a blank look. It could have been any one of a dozen soirees at which he'd wanted to kill himself.

"I'm afraid he's been rather distracted these past few days," said Magda. "That horrible murder took place just outside his rehearsal room. He was even questioned by the police-"

"Oh, I say, what fun!" said Lady Frances, clapping her hands delightedly. "Were you a witness? Will you be obliged to testify in court?"

"I'm afraid I didn't see the incident, Lady Frances," said Elliott, mustering a smile, "but I'm doing my best to find out about it."

Magda narrowed her eyes. "What do you mean?"

"In fact," he said, stepping closer to Lady Frances, before Magda could intercede, "I'm investigating at this moment. I don't suppose you'd lend me a sixpence? I'm trying to extract some information from a particularly reticent cabbie."

Magda made a strangled noise and grabbed his arm, drawing him away from Lady Frances. "Elliott, this is the daughter of the Earl of Devonshire," she hissed. "If you think she's even seen a sixpence-"

But Lady Frances was already fumbling in her purse. "I have half a sovereign."

"Really, Frances, you mustn't encourage him-"

"Frances, you're a ministering angel," said Elliott, taking the proffered coin. "When I solve this case, I'll be sure to mention your part in it."

Magda glared at him, and then turned to Lady Frances with a bright, breezy smile. "Do go on without me, my dear Frances. I'd like to talk to my brother about this terrible business of the murder, and I'm sure he'll be good enough to escort me the rest of the way."

They watched Lady Frances climb back into her carriage with an audible creaking of corsetry, and then Magda rounded on him.

"What in God's name do you think you're doing? That woman could ruin your career and my prospects forever if she had a mind to!"

"Lucky for us she doesn't have a mind at all," said Elliott. "Anyway, do you think these people are your friends? Do you know what they're saying about this wedding, and why it's happening in such a hurry? They're saying you told the Duke you were an heiress, and you're trying to get the ring on your finger before he finds out it was a lie."

"It's a different world here," Magda snapped. "It's unusual for someone in Fitzwilliam's situation to marry for love, so naturally they're shocked. But they're coming round to the idea. They could have snubbed me, Elliott. They could have refused to acknowledge this engagement at all. A few comments behind my back was the very least I expected!"

Elliott hesitated, realizing for the first time that, during all those weeks of soirees and small-talk, she had been preparing for a battle. Perhaps that was the way she battled – by dressing very smartly and talking very amicably. She had always been prepared to fight for the man she loved, which might just mean that she'd be inclined to sympathize with his situation, if he confided in her.

"Did the police question you?" she asked in a calmer tone, taking his hand and placing it on her arm as they set out down St Aldates.

Elliott nodded. "Some young Constable with a pink face and a large Adam's apple."

"A Constable? I would have thought they'd send an Inspector at the very least. You're almost the brother-in-law of the Duke of Buckingham!"

"Almost," said Elliott, picking up on the most crucial word in that sentence. Still, he wasn't interested in starting a fight with her, so he went on, "I told them I didn't see anything."

"That's good."

"Magda, I did see something."

"What? What are you talking about?"

"The dead girl's not dead," he said, trying – and failing – to suppress the enthusiasm in his voice. "And she's beautiful. I know her, Magda – as if we've been friends all our lives – and she knows me, I know it-"

Magda raised a hand. "Wait a minute. Go back to the beginning. The dead girl is-?"

"Not dead," said Elliott firmly. "Or there are two of her, or something. I saw the corpse on the steps of the Music Rooms, and then I saw the same woman standing over her – more alike than a twin – and she saw me." He hesitated and squeezed Magda's arm, probably a little too hard. "Only don't tell anyone, Magda. She's running from something awful – she must be, to fake her own death – and, until we know who we can trust, we mustn't say a word."

"I still don't understand. What happened when she saw you?"

"Nothing," said Elliott, waving a hand wildly. "And everything. She recognized me, and I recognized her. And then she started running, and I couldn't catch her-"

"Good God, why were you trying?"

Elliott stared at her. He thought it would be too melodramatic to say 'because I love her', and yet this seemed to be what Magda heard anyway, because she exclaimed, "You've never even spoken to her!"

"It doesn't matter." 

"You've got to be in Paris in two weeks!"

"No, I haven't, Magda." He pulled her under the awning of the nearest shop, out of the way of the other pedestrians. "Listen to me, Magda. I'm not doing it anymore."

"But Fitzwilliam-"

"No," said Elliott, shaking his head. He found that – in this moment of supreme exasperation – he was suddenly able to be calm and kindly. It was the certainty that had been urging him on all morning. Somehow, it gave him room to breathe, even in streets rammed solid with the press of humanity.

"You'll be a Duchess, Magda. There's no-one on earth who can stop you – least of all these snide, whey-faced aristocrats. You don't need me playing concerts and raising your stock in society. Your stock is already sky-high. You're a formidable woman. But I'm not taking orders from you anymore. I'm going after her. And, if I come back to Oxford – or play another concert – it'll be because I want to. You don't have to look after me anymore. I'm twenty-four now."

"You say that as though it's ancient," said Magda, in a choked voice.

"You're right. It's immaterial. I'd be ready to go off on my own if I'd seen this woman at the age of twelve. I've met someone I want to protect – and that means I'm not a child anymore, whatever my age happens to be."

Magda gave him a feeble slap on the chest. It seemed to be half a punishment and half a capitulation.

"All right," she said, still in that hoarse, throaty voice. "Have it your way, little brother."

She took out her handkerchief and dabbed at her eyes for a moment. And then she was confident, capable Magda once more, and they were continuing, arm-in-arm, down St Aldates.

"Although I still think you ought to be careful," she said. "Are you quite sure you want to marry a new-breed? Have children with a new-breed?"

"Don't try to tell me they're savages-"

"I would never say that," said Magda, giving him a much harder slap on the chest. "I'm only saying that, through no fault of their own, they've been treated badly, and some of them might still harbour a grudge."

Elliott – still thankfully in the grip of all that calm kindness – said, "Do you know your Duke's a good man?"

"Of course I do."

"How? He's never been tested. He's never had to make a difficult choice in his life. And don't give me any nonsense about how he comes from noble stock. How do you know he's a good man?"

"I just know!"

"Well, exactly," said Elliott. "So do I."

"But I've at least had a few months of acquaintance in which to form this opinion! You've never even spoken to your new-breed!"

"Talking is an over-rated method of communication," said Elliott. And he didn't add that he had come to this conclusion through years of one-sided arguments with her.

"Where am I escorting you to, anyway?" he asked, as they approached the powder-blue dome of Tom Tower at the entrance to Christchurch College.

"Just here," said Magda, letting a faint, smug smile settle on her lips. "Frances and I are taking tea with the Reverend Dodgson." When this failed to get a reaction from him, she added, "Better known as Lewis Carroll? The author of the Alice books?"

"Oh," said Elliott. He paused, and then went on, "Did you bring a little girl with you?"

Magda smacked him in the chest for a third and final time. "Elliott! That's just a vulgar rumour! Now kiss me for luck," she said, raising the veil on her hat and proffering her cheek. "I'm hoping he'll dedicate his next novel to me."

"You don't need luck," said Elliott. But he kissed her anyway.