There was an easy camaraderie to the Domino Room that belied its showy décor - high ceilings, mirrored walls, pillars like great trees in a fanciful forest, an overall colour scheme of peacock blue and gold. Bookies, artists, journalists, tarts, models, the would-bes and the has-beens, all mixed here with people from their own worlds and from that genteel one in which nobody worked but everybody was well off. Generosity, in the form of the casual invitation or the standing of drinks with somebody’s last shilling, was the rule. Denton had learned to love the place. He loved to keep his hat on, to lounge against a banquette. You could do that in the Domino Room, and a good deal more - like last night.

Denton looked around and saw Frank Harris in his usual place; he moved to him and stood until the man looked up with hangover-reddened eyes. Harris groaned.

Denton collapsed beside him, ordered a milky coffee - a house speciality - and choucroute, part of the Royal’s French past. When he said, by way of making conversation, how much he liked the Café, Harris growled, ‘This place is the boue in nostalgie de la boue. It appeals to the worst in all of us, and we all respond with a joy bordering on indecency.’

‘Like last night.’

Harris groaned again. ‘Did you drink as much as I did?’

‘We stood on a table and bullied people into drinking to Wilde.’

Harris put a hand on his forehead. ‘There’s a stage after you’ve been drunk where you think you’ll kill yourself, and then there’s a stage of absolute euphoria. I think that I’d have been wiser to stop at euphoria and not drunk anything tonight.’ He sighed. ‘Not to mention what I had with lunch and the one or two before.’ He sat back in his chair and clutched his head.

Denton said, ‘I need a bit of advice.’ Harris was supposed to have an encyclopedic knowledge of the darker side of London - indeed, of the darker side of a lot of things. ‘Who can tell me about vice in the East End?’

Harris turned his red eyes on him, looked at him for long seconds as if he’d forgotten who he was. ‘You’re talking to an expert,’ he said.

‘There was a girl murdered there last night. I want to know who she was - where she came from, who her—’

‘East End?’

‘Well, the Minories.’

With his head back, Harris looked at Denton as if he were looking into a too bright light. ‘What’s the allure of a murdered tart? Idea for a book?’

Denton mentioned Mulcahy, said only that the man had told him a wild tale and been terrified - his now-familiar recitation.

Harris wrinkled his nose and stuck out his lips, then rubbed his eyes. ‘You know Ruth Castle?’

‘Mrs Castle?’ She was a famous madam; of course he knew her. ‘We all know Mrs Castle.’

Harris laughed. ‘Could make a comic song of that. “Oh, we all know Mrs Castle here in London—”’ He sang it a bit tunelessly. ‘What the hell rhymes with London?’

‘Done-done. Undone.’ He looked at Harris’s empty glass. ‘Y ’know, you’d do best to go home.’

‘At this hour? My God, what would people say?’

‘Why Mrs Castle?’

‘Why not Mrs Castle? What are we talking about?’

‘Vice in the East End.’

Harris waved a hand. ‘She knows everything. Tell her I sent you. Better yet, don’t tell her I sent you; I think she had me thrown out last time. But go and see her. Fount of knowledge.’ Harris ordered himself another brandy and began to lecture about Bohemianism and the decline of art. Denton, finishing his choucroute as fast as he could eat, muttered a goodbye and got up.

He left Harris trying to start an argument about Fabianism with a man he didn’t know and went out. He debated following Harris’s advice to talk to Mrs Castle that night but thought his own advice to Harris was best: early to bed.

He poked the fire and put the poker back in its iron stand and heard a sound that might have been the poker hitting another piece of metal but that might have been something else. He stood still, listening. He really believed the sound had come from somewhere else. Outside? Most likely not; it had been too muffled. And closer.

‘Sergeant?’

They had had trouble with rats for a while. The sound was not unlike that of an animal dropping to the floor from a table. When they had had rats, a cat had got in once; it had made that sound, dropping in the dark on a rat to break its back.

Denton hated rats. He took up the poker again.

The gas light was on by the door nearest him, the only light in the long room other than the coal fire. If Atkins had been home, a lamp at the far end near his door would probably have been lit, too; instead, the room receded into darkness, past the dumb waiter, past the alcove on the left where the spirit stove and the makeshift pantry were, to the stairs and the window at their foot, now only a silvered reflection of the light.

Later, he would think he should have taken the derringer, but then he would think that it wouldn’t have mattered. When the attack came, it came so fast that he was unable fully to react, and it came from his left side; the derringer would have been in his right. The poker - well, it saved his life, if not his arm.

He had started to pass the opening to the pantry alcove. He was listening, his head slightly cocked, and he was thinking that the light near Atkins’s door should have been on, whether Atkins was there or not. He had reached the point of wondering why the light was out, and he was just beginning to appreciate an alien smell that was reaching his nose, when the attacker came in a blurred silver slash from the black alcove. Denton reacted away, turning, raising his left arm against that shining slice through the darkness, and his arm caught fire as something ripped through the coat sleeve and slashed him from elbow to wrist. He heard himself gasp in shock and something like indignation, then rage at himself for being so stupid, and then the blade, which had caught for an instant in the sleeve buttons, tore free and was being raked across his mid-section.

The attacker tried to move in closer; a hand grabbed at his coat, tried to pull him. Denton swung the poker against the man’s side, then higher against the back of his head. He caught the knife arm with his left hand somewhere above the elbow. The knife was being held for a downward blow - not a knife fighter’s grip, Denton would think later; a real fighter came in from below - and so, for the seconds that Denton could grip the upper arm before his own bleeding forearm weakened, the blade could only graze his ribs.

The attacker was a big man, and he stank. He stank of sweat and urine and of too long without washing. He had black hair, eyes that looked red in the thin light; his lower face was covered. The eyes were wide, frantic, as he tried to put the knife in and was held back. Then Denton dropped the poker and caught the face, his fingers trying to dig into the eyes, and pushed the head backwards as he brought his knee up.

The man roared. His weight came off Denton’s arms as he surged back, trying to free the knife hand. Denton, his feet planted now, pushed; the attacker slammed back against the pantry arch; Denton turned his body into the knife, grabbed the arm with his right hand and slid the left down to the wrist. He was suddenly aware of the blood that was streaming down his arm, making the other man’s wrist slippery.

Denton crashed the attacker’s arm down against his right knee, trying to break it, and the man moaned. Denton’s head was grabbed from behind and he was spun towards the wall, but he recovered and turned back, and, panting, the attacker fled down the long room towards the light, and then his steps thudded down the stairs and the front door slammed.

Denton was stunned. He leaned back against the wall, trying to clear his head. When he could think and move, he tottered down to the light, holding his left arm with a thumb in the crook of the elbow because he thought he could stop the bleeding. The light proved that idea foolish; the blood was coming from the outside of the arm; it had soaked the coat sleeve black and was running down his fingers and dripping in almost a stream on to the carpet. A trail of drops showed where he had come. He tried a crude tourniquet made from an embroidered runner from a table. It was a hideous thing; he felt a moment’s illogical satisfaction in seeing it soaked with blood. Still, twisted around his upper arm, it slowed the flow only a little.

He would get light-headed and then weak, he thought. He needed a doctor.

He headed down the stairs and out to the street. The Lamb was closed, the street empty. Somebody described to him as ‘a foreigner’ had a surgery down opposite Coram’s; would he be there at this hour? Denton began to walk in that direction, then broke into a trot. It was at that point that he saw a figure turn the corner and head his way.

It was Atkins.

Denton hurried towards him, his arm held out like an offering, blood behind him in round spatters right to his front door.

‘I’ve no idea.’

‘You’d just got home. You heard a noise. You went to investigate.’

‘Yes - as I’ve told you.’

Denton was lying in the ‘foreigner’s’ surgery; the doctor proved to be a Polish Jew who spoke English with a music-hall accent but who was skilled at his art. He was swabbing Denton’s arm with carbolic and then taking stitches while the constable made notes and another policeman stood at the door, as if either Denton or the doctor might try to run away. Atkins was slumped in an armchair, fanning himself with his bowler and looking desperate.

‘I think it was attempted burglary, Tim,’ the first constable said to the other one, who grunted.

‘I am hurting?’ the doctor said. He had given Denton morphine to take the edge off the pain, but the cut was deep and long, and he had to make many stitches.

‘Not so bad.’

‘You behafe well.’

Denton grunted.

‘I am giffing you laudanum for after,’ the doctor said. He had a rather long beard, a bald pate with a circle of black hair, like a monk. ‘You don’t sleep without.’

‘Anything missing?’ the constable said.

‘I didn’t look.’

‘Didn’t look, Tim.’ The constable consulted his notebook. ‘My advice, look first thing tomorrow.’

‘I’ll do that,’ Atkins said. ‘Crikey, don’t you coppers realize the man’s been stabbed?’

‘Now, now!’ The constable looked severe. ‘Detectives will want a full inventory. They often close a case that way, knowing what’s missing.’

‘What, they see what’s missing so they close it?’ Atkins sneered. ‘Regular Sherlock Bleeding Holmeses, they must be.’

‘Now, now!’ The constable moved to stand in front of Atkins. ‘You mind your mouth, my lad.’

‘Can’t you see I’m in a nervous state?’ Atkins looked up at him, gauged the constable’s age, which was certainly less than his own. ‘“My lad.” My hat!’

‘He’s in shock, Tim,’ the constable said to the other one, who grunted. The constable returned to Denton. ‘Black hair, smelled bad, tall. Correct?’

The doctor looked up from his work. ‘When you are finishing? You vex my patient.’

‘I wot?’

Atkins twirled his hat. ‘“Vex.” It means to irritate, to bother, to be a royal pain in the bum. Couldn’t apply to you, oh, no!’

The constable turned. ‘Now, I’m telling you—’ He pointed a large, blunt finger. ‘I don’t mind making an arrest for interfering with the work of a constable. Get me?’

Denton flinched as the needle went into tissue. ‘Give it over, Sergeant. He’s doing his job as best he can.’ He moved a leg, which was going to sleep in the uncomfortable position required by the leather couch he was lying on. ‘Yes, black hair, tall. Big man - heavier than I am. Strong. Maybe a little gone to fat; his arms felt big but not muscular. Foul breath. Hadn’t washed - same thing with his teeth, I think. As if he’d been living rough.’

‘A tramp? Lots of tramps turn their hand to burglary when they’ve a chance. Leave a window unlocked, did you?’

Atkins groaned. Denton said, more feebly than he’d intended, that a detective could look to all that in the morning. Then, perhaps only because the doctor wasn’t finished and the constables were more comfortable in the surgery than on the street, they went through it all again. The doctor finished the arm and wrapped it tight in white bandage, which quickly discoloured with a line of oozing blood. He turned his attention to the ribs, which Denton had been surprised to find were cut, swabbing them with carbolic, which felt to Denton like live coals. His shirt was slashed, the suit jacket as well.

Denton found it hard to stand straight. Atkins paid the doctor out of Denton’s wallet, made a face when he saw it was then almost empty. When Denton thanked him, the doctor - still in a nightshirt, a cardigan pulled over it - smiled and said they were neighbours. He saw Denton often, he said. ‘My name is Bernat. For the next time.’ He grinned. ‘If you are cutting yourself at the shaving.’ He gave Atkins a folded paper. ‘Laudanum pills. I am old-fashion doctor - very believing of laudanum for pain and sleeping. Make him take them, please.’

Atkins helped Denton along the street. The two policemen followed them to the front door, where the one who grunted was to take up a post for the rest of the night. ‘Just in case,’ the constable said. Woozily, weakly, Denton thought, In case of what?

It was so hard for him to get up the stairs to the first floor that he asked Atkins to make him a bed in the easy chair. ‘All I want to do is sleep.’ Atkins picked up the hat and overcoat Denton had dropped there two hours earlier and came back with pillows, a blanket, his slippers and the derringer, which had been in the coat pocket. He put the little pistol on the table next to Denton’s chair, then drew a pitcher of water in the pantry and poured a glass and gave him two of the laudanum pills. ‘Medical officer says you’re to take these. Orders.’

‘I had morphine.’

‘Do as you’re told, Corporal.’

Denton took the pills, sipped the water.

‘You think it was him, don’t you,’ Atkins said.

Denton stared at him, shook his head. He was too wobbly to think. He waved a finger at the decanter. ‘Nightcap?’

‘It’s practically bloody morning, General!’

Denton stretched his feet out. ‘I feel like hell. A little, Sergeant.’

Atkins set the glass where he could reach it. ‘Medical officer didn’t say nothing about mixing laudanum with brandy. Be it on your head.’

‘It isn’t my head, it’s my arm. And my damned mid-section. ’ He sipped. The brandy, the taste of it, the strike of it, was far more satisfying than any pills. ‘Go to bed, Sergeant.’

Atkins was looking at the carpets. ‘Be a right treat, getting the bloodstains out of these. No bleeding rest for the weary!’

‘Tomorrow, tomorrow.’

Atkins grunted and disappeared through his doorway, glad, apparently to get to his own spaces at last.

And then, at the far end of the long room, Atkins’s door was opening. A hand, turning out the gaslight. The man’s smell reaching out ahead of him.

Denton watched him come down the room. Smelled him. Same smell, same man. Bottom part of his face covered again. He seemed to be coming a great distance, walking and walking and making no headway. Then suddenly he was there. With the knife.

Denton wanted to open his mouth and call out. He wanted to stand, to run to the door. A policeman was just outside.

He couldn’t make enough sound to summon him.

He looked at the man’s eyes, which looked at his. The man was sweating. Denton tried to force his hand to pick up the derringer and aim it, but he could command the hand only to move under the blanket to the arm of the chair and then, in a spasm, strike the edge of the table. Seeing the movement, the man with the knife moved faster. Their eyes remained locked. The man was trying to assess how best to do it, he thought, changing his grip on the knife and bringing it across his own body as if for a backhand stroke, as if he would perhaps grab Denton’s hair with his left hand and sweep the blade across his throat. As he had murdered Stella Minter.

Denton’s palm rested on the derringer.

The man with the knife moved.

Denton willed his arm to raise the gun, willed his eyes to aim, willed his finger to pull the trigger, but all that happened was that the gun, still on the table, went off, burning a crease across the tabletop, the bullet smashing through the thin, pie-crust edging and going into the wall.

The man with the knife cried out. He turned and raced back down the room, and Denton heard the sound of smashing glass. He was using something, maybe a foot, a boot, to break out the glass from the window at the foot of the stairs. The cooler air caressed Denton’s face; there was silence; he smelled burning coal and the last of the man’s stench. He tried again to call out, but nothing came.

Then a pounding on the front door. The policeman had heard the shot. Denton waited for Atkins to open the door. The pounding went on. Where was Atkins? But the man with the knife had come from Atkins’s doorway, so where had Atkins been then?

He was waiting for us, Denton thought. He never left the house. He slammed the front door but stayed inside, and he hid down in Atkins’s rooms until he could deal with Atkins, and then he came up to deal with me.

‘Sergeant,’ he managed to croak. His voice was expressionless. He was still covered in snow. Like being his own ghost.

Outside, the policeman was shouting, then blowing his whistle. Denton pushed with his right hand and the little table on which the derringer rested toppled over. Denton rolled himself off the chair. He lay on the floor, then pulled himself to his knees, up to a crouch to shamble towards the door. A huge effort to open it, then beyond it the stairs down; he held on to the banister with both hands but still fell halfway and wound up sitting at the bottom. He crawled to the door and opened it.

The policeman’s face was terrified, then enraged. Another whistle was sounding somewhere. Denton tried to speak.