Sherlock didn't hesitate to throw open the lid of a large metal skip, grab the rim, and hoist himself up. But before he could tip himself in, John spoke:

'Sir, should I?'

Sherlock looked over his shoulder, balancing where he was hoisted. 'Should you what?'

'Search the skip? You'll not want to dirty your clothes, sir, I expect.'

They had shed their outer blue jumpsuits at Lauriston Gardens before dashing away, and Sherlock hadn't explained where to. But John cottoned on soon enough, when he saw the skip and what Sherlock was planning to do. Now, the stink of London rubbish wafted over them, and a lesser detective may very well have sent in an assistant to do the dirty work. But he was too keyed up to let John have all the fun. He flashed John a smile, lifted his leg, and launched himself inside the skip.

Then he turned around and extended a hand to the shorter man.

'Come join the search party,' he said. John seemed uncertain as he looked at Sherlock's proffered hand. Then, deciding, he smiled a restrained sort of smile and gripped the hand, letting Sherlock pull him up and in.

'You won't miss it,' said Sherlock, beginning to sift. 'As you so rightly pointed out, it will be a rather shocking shade of pink.'

But the dead woman's suitcase was not in the first skip they searched, nor the second, nor the third.

'Don't worry, we won't be doing this all night,' said Sherlock, undeterred, as they left the fourth skip and its rotting fish heads, diapers, and spoilt Chinese. He took a quick whiff of himself. A little rank, perhaps, but nothing the night air wouldn't help disperse. They turned a corner and joined the busy streets of London. 'We're working within limits: time and space. The killer will have noticed his mistake quickly, and quickly tried to get rid of it. The suitcase will therefore be within an area a tight radius from the crime scene, and there are a limited number of skips in that area. I base my calculations on three factors. One: the approximate time of death suggests . . .'

But he trailed off when he realised that he was talking to himself, and walking alone.

Sherlock turned, eyes scanning for John. He spotted him fifteen yards back, standing stock-still between the kerb and the buildings while foot traffic flowed around him. His bracelets were alight and flashing green.

It occurred to Sherlock that, since bringing John home, they had never been on the streets together when the bracelets had gone off. In fact, now he thought of it, he'd never had to deal with those damn bracelets at all. When he was a child going on walks with Redbeard, the bracelets had not yet been made digital—they were only leather bands and worn only on the left wrist, inscribed with the registration number for identifying purposes.

But as the laws and technologies evolved, the bracelets had, too. Now, they were black bands of electronic flexiglass embedded with a GPS tracker, shiny and unassuming until activated with cautionary lights. All wards had to wear them when in public spaces, no exceptions, and when they lit up, all wards, no matter the circumstance, had to come to a standstill. Failure to do so resulted in a mild electric shock to the wrists, a reminder to stop moving. Failure to comply with that yielded a higher level of shock too unpleasant to ignore. Rarely did Sherlock ever see a ward walking with bracelets aglow. They were always standing still. As for himself, he was in the habit of ignoring the lights altogether, like most people did.

Then again, rarely were wards out past curfew, like John was now. At night, lighted bracelets were something of a spectacle.

Sherlock jogged back to him, scowling at the pedestrians who scowled at John, mistakenly judging him for being in public past curfew without his host.

'Sorry, sir,' said John sheepishly, clenching his hands into fists while the bracelets continued to flash green.

'Never mind,' said Sherlock waving away the apology. He glanced around to see if any other greens lights were flashing, but it seemed John was the only ward on this street. That meant it was only a matter of time . . . And sure enough, the patrol officer had spotted him and was making his way closer, tablet in hand.

'You the host?' said the officer, plucking the tablet pen from his pocket.

'Yes,' said Sherlock tiredly.

'Host ID, if you please, sir.' Then, to John, 'Registration tattoo.'

John started unzipping his coat.

'No need,' said the officer. 'Just push up your sleeve.'

'It's on the back of his neck,' Sherlock explained as he dug into his wallet for the host ID card. This was ridiculous. Everyone was staring, as if Sherlock had done something wrong, as if they hadn't—each one of them—been through a spot check before with their own wards. But it was always a scene. When bracelets went green, it was more often than not a routine spot check; but blue meant there had been a report—unruly behaviour, suspected thievery, and the like. When the bracelets flashed red, however, it meant they had a runner, and all innocent wards in the lighted area had to prove it wasn't them.

The officer helped John pull down the collar of his shirt to access the tattoo and scanned it into his tablet. Then he cross-checked it with Sherlock's host ID card. All told, it was quick and efficient, but that didn't mean it wasn't a pain in the arse. They were in the middle of a case, after all.

'Looks to be in order,' the officer said, satisfied. He waved his tablet pen-wand over the bracelets, first the right, then the left, deactivating them, and they returned to black. 'Don't let him stay up too late, though, eh?' And just as quickly as the patrol officer came, he left.

'Insufferable,' Sherlock murmured.

'Sorry, sir,' John said again.

'God no, not you, John. Come on. Our night is far from over.'

They fell into step again. This time, Sherlock didn't let John lag behind: he was more mindful of the limp, more conscientious of John's tendency to place himself half a step behind, and more determined to keep him at his tight right hand.

'Does that happen often when you go out?' Sherlock asked. 'Your bracelets lighting up and everything?'

'Regular enough, sir.'

'Don't you just hate it?'

John was slow to answer. 'Just the way of it, I suppose.'

'Maybe. But you can still hate it.'

When John neither agreed nor disagreed, Sherlock pushed a little further. 'Doesn't it make you angry, sometimes?'

'I don't know,' John said, noncommittally, like he didn't wish to have an opinion on the matter.

'You know you're allowed.'

'Sir?'

'To get angry. To hate things. Go on then. Tell me one thing—just one—that you hate.'

'No, no,' said John, shaking his head with a nervous sort of laugh, like he was being tested and had spotted it before he fell into a trap.

'Really. One thing you hate, and I'll drop the matter.'

'Um.' It was nearly half a street later before John spoke again. 'I don't much fancy apples.'

Sherlock looked at him, startled. Of all the things on the planet for John to despise, that he should despise, and he picked apples? Sherlock threw back his head and laughed. 'You hate apples!'

'Well, I don't much fancy them,' John amended.

'No, no. Go on and say it: I hate apples. Say it!' He smiled broadly, wanting John to know he was in a space free from consequences of taking a stance, and such a mild stance it was.

'Well then,' said John, grinning back, shyly, as was his way, 'I . . . hate apples.'

Sherlock laughed again.

'I do. I hate them,' said John, more boldly.

'Glad to hear it! No more apples on Baker Street!'

'But if you should like them, sir—'

'Nope. Don't care much for them myself. There's no point to them. Aha! This way, John. End of the car park, I see another skip.'

They had discovered, four skips ago, that it was more efficient if Sherlock helped lift John into the skip first, which he did now. But just as he was grabbing top of the wall to pull himself up and in after him, he heard John cry out, 'It's here!'

There was a shuffle and bang and the sound of squishy rubbish in plastic bags, and then John's head reappeared, followed by an arm bearing a small pink suitcase, like he'd just caught a large fish.

'Excellent, John! Ha ha! I knew it! I knew we'd find it. Pass it here.'

Face aglow, John heaved the suitcase over the rim of the skip and into Sherlock's outstretched hands. When he was on the ground again himself, he looked at Sherlock expectantly, wondering what would happen next. 'Will you call Mr Lestrade?' he asked.

Sherlock winced. He should call Lestrade, certainly. He knew that. But then their fun would be over. Lestrade might ordinarily permit Sherlock to continue to tag along in pursuit of the killer, but not if he had his ward in tow. The crime scene had been pushing things a bit far, almost too far, and though Lestrade was a tolerant man and often submitted to Sherlock's bullying, when he put his foot down, he put it down hard.

But John . . . He was having fun. Sherlock knew it. He could see it in the man's face, and it gutted him to think that they would have to call it quits and return to the quiet flat, to do all those mundane things that people do, like sleep. He wanted to give John something more.

'Not just yet,' he said. 'You and I? We still have work to do.'


They returned to the flat, but not to sleep.

'Go ahead and unzip it,' said Sherlock, letting John get some hands-on experience.

John didn't question him. Likely, he had never been in a situation before where he had to worry about contaminating or tampering with evidence, and Sherlock frankly didn't care. He didn't need forensics, not when he had the science of deduction as his primary tool. Together, they rummaged through the contents of the pink suitcase, turning up nothing more exciting than bras and earplugs. But it wasn't what was in the suitcase that Sherlock found significant. It was what wasn't.

'Notice anything missing?' he asked. He did so enjoy watching John's brain at work.

'Missing, sir?'

'Everything you'd expect is in this suitcase,' Sherlock said, digging a hand through. 'Pyjamas, change of clothes, toiletries case . . .' Then he added, with emphasis: 'Charger.'

John stared hard at the contents. 'You mean . . . her phone?'

'Precisely! Phone wasn't on the body! So that means . . .' He made an encouraging gesture with his hand, eager to see if John would arrive at the obvious conclusion on his own.

'It means . . .' John's eyebrows shot up. 'The killer has her phone!'

Sherlock leapt out of his chair and turned a circle. 'Yes! Exactly yes! And we have her number. It's on the luggage!' He snapped his mobile up out of his pocket and tossed it to John, who caught it against his chest. 'Here, I want you to send a text.'

'Oh. I . . . I . . .' He looked down at the phone, and when his eyes returned to Sherlock, he looked frightened. 'I don't think I should, sir.'

'Nonsense, it's fine.'

'No, I . . .' That old look of shame was beginning to rise in his face. Sherlock knew it well, so often he had seen it, and it took him back to the early days before Christmas. Not quite understanding (did the thought of texting a murderer, even from a safe distance, frighten him?) but keen to keep the good feeling of the evening alive, Sherlock swiftly intervened.

'Oh wait,' he said. 'I have the number here. Let me see that.'

He reclaimed the phone. John, spared the task, visibly relaxed. So Sherlock entered the text himself:

What happened at
Lauriston Gdns? I must
have blacked out
.

He paused, thinking. Then he added:

221B Baker Street.

'And now we wait.' He sank into his chair, trying for a patient pose, but his legs were restless and his whole body needed to fidget. He wouldn't last.

A modicum of John's shyness had returned, but not enough to preclude him from asking, 'For what, sir?'

Sherlock shot forward. 'Imagine it, John. You're the killer. You've left your latest victim dying, presumably dead, on the upper floor of an abandoned complex. But you still have her phone. When you chucked the luggage, you forgot about the phone. It's still in your possession. Suddenly, a text! What happened to me? I must have blacked out! Maybe she's not dead after all! What do you do? Ignore it? Throw the phone away at the nearest opportunity? Dare you text back? If she really is alive, she'll know your face, she'll identify you to police. But you have to be sure. So you—'

The phone suddenly started ringing. Their heads swivelled as one to stare at it, John in terror, Sherlock in delight. 'You panic!'

He was on his feet again, exhilarated, agitated. He flew to the window, needing to look, but he knew it was pointless. It was too soon for the murderer to have arrived. Still, he could barely contain himself. He hadn't had a case this interesting in months.

The phone stopped ringing.

'That was him!' said John, infected with Sherlock's excitement. 'That was the killer!'

'Indeed,' said Sherlock, flashing him a smile from the window.

'Then . . . ?'

'Go on. Ask.'

'Why didn't you answer? Don't you need to find out who he is?'

'Oh, I shall. But do you really think he would tell me that over the phone?'

John shook his head. 'I suppose not.'

'Of course he wouldn't. That's why I've invited him here directly.'

His gasp was silent, but John's face said it all. 'Here, sir? To Baker Street?'

Sherlock chuckled. John's reactions were just too precious.

'Isn't that . . . dangerous?'

'Hardly. He may be a murderer, John, but he's not a violent one. So to speak. Poison is the weapon of choice when one doesn't want to get his hands dirty.'

'But sir. Surely, he'll not want to get caught. He's got away with it so far, hasn't he? So he'll not be foolish enough to come here.'

'No, he's just brilliant enough.'

John balked.

'I do love the brilliant ones,' Sherlock carried on, rubbing his hands together deliciously as he paced the room. 'They're always so desperate to get caught.'

'Why?' asked John, incredulous.

'Appreciation! Applause! At long last, the spotlight. That's the frailty of genius, John. It needs an audience. Now let's think.'

He needed to work through the problem, and John was the perfect sounding board. Much better than ol' Billy, at any rate.

'We know his victims were abducted. They all disappeared from busy streets, crowded places, but nobody saw them go. Plus, the abductor was a stranger to them. Must have been.'

'Why's that, sir?' asked John.

'Simple. If not a stranger, then the killer was a familiar face, someone they trusted. But then the killer would have to know them all, wouldn't he? Yet there is nothing that connects any of the victims.'

'Might there be more than one, then?'

Sherlock grinned. It really was a clever hypothesis, though a wrong one. 'Maybe,' he conceded. 'But I doubt it. Multiple killers suggests either a gang or a copycat. Gangs are not nearly so organised, and copycats aren't nearly so consistent. The modus operandi of a serial killer is one of working alone. I am confident we are chasing only one man. So!' He continued pacing, once in a while eyeing the street, but he suspected that it was still too soon. 'A stranger to them all. And yet, at the same time, someone they trusted.'

'Why would they trust a stranger?'

'Now there's the question!' Sherlock pronounced. 'Think! Who do we trust, even though we don't know them? Who passes unnoticed wherever they go? Who hunts in the middle of a crowd?'

'I dunno, sir. Who?'

'We shall soon find out.'

For the next few minutes, Sherlock retold the story of how he had once tracked down a house burglar who had struck more than a dozen homes in only two nights with nothing to go on but the fact that all the burgled flats had chrome doorknobs. Then, just as he was reaching the climax of his tale, they heard a car door slam shut down on the street. John, who had been riveted to the tale, sprang to his feet, and Sherlock hopped excitedly to the window, at which point his happy bubble burst.

'Oh no,' he groaned. 'No no no!' He whirled back. 'John, the suitcase! Zip it up, hide it!' But there was a parade of footsteps on the stair. 'Shit, too late.' He leapt over a chair to plant himself squarely in the middle of the room and face the door, hands akimbo and a haughty, indignant expression at the ready.

Lestrade was first through the door. To Sherlock's disgust, half a dozen officers followed, Donovan and Anderson included.

'What the hell do you think you're doing!' he demanded. 'You can't just break into my flat! There are laws!'

'Since when do you care about laws? And besides, I'm not breaking in,' said Lestrade, squaring off with him, nearly toe to toe. 'It's a drugs bust.'

'Sir,' said John timidly from behind him. Sherlock glanced back and saw he was standing in front of the suitcase as though to shield it with his body. His eyes questioned him, wondering what he should do. Sherlock sighed, and just shook his head to indicate that the game was up.

'Search high and low, boys!' Lestrade shouted. 'We're looking for needles, suspicious white powders, pipes, rolled paper, anything at all!'

'This is absurd,' Sherlock spat.

'My yes, nothing more absurd than addiction,' Lestrade retorted. 'Leads to all sorts of irrational behaviours.'

'Pardon, Mr Lestrade.'

To Sherlock's surprise, John stepped forward to stand at his right hand. Lestrade, too, looked taken aback. Wards didn't usually talk to law enforcement, unless explicitly directed to.

'I've cleaned this flat top to bottom,' he said, 'and you're most welcome to look, all night if you must, but I can promise you'll not find anything you could call recreational. Mr Holmes doesn't even smoke.'

Lestrade gaped at him for a moment before saying, 'And what would you know about it? Would you even know the difference between heroin and sugar if you came across it?'

'Yes sir, I would,' said John humbly, and, having said his piece, took a step back.

Sherlock was both touched by John's defence of him, and troubled by his final assertion. But given the present company, he turned back to Lestrade and said, 'Well. There you have it.'

'I was just about to say the same thing,' said Lestrade, pushing past him to where the pink suitcase lay on the floor between the two facing chairs. He ran a hand through his hair. 'Sherlock, how many times do we have to go through this? You can't just withhold evidence! And you rummaged through it! For the love of . . . This is my case. I'm letting you in, but you haveto work with me.' He shot a glance at John as though to drive home a point. 'You can't just go off on your own!'

Annoyed at the implication regarding John, Sherlock waved his fingers in Lestrade's face. 'You all just slow me down. Hey, don't touch those!' he shouted toward the kitchen.

'Are these human eyes?' said Donovan, holding aloft a jar and looking repulsed.

'Pig, ma'am,' said John softly.

'They're for an experiment,' Sherlock griped.

'They were in the microwave!'

'Lestrade, seriously, get your people out of here.'

'What, because we slow you down? Find out who Rachel is on your own, did you?'

'Oh.' Sherlock paused, his curiosity warring with his indignation. 'Very well. Who is she?'

'Rachel is Jennifer Wilson's nine-year-old ward.'

'The ward?' A note to the ward? Or a note about the ward? The effort it must have taken, to scratch those letters into the floor before she died, had surely been excruciating, painful. What had she been trying to say?

'Waste of effort, if you ask me,' Anderson piped up from the kitchen, gloved hand poised on the shelf behind an open cupboard. 'If she wanted to do something useful in her last moments, she should have scratched the name of her killer!'

Sherlock turned, eyes blazing. 'Anderson, don't talk. You lower the IQ of the whole street.' To Lestrade, 'Is the ward safe? Was there any harm done to the child?'

'Yeah, yeah, she's fine,' Lestrade said. 'At home in Cardiff, with her host. Mr Wilson, that is. So what? Why scratch the name into the floor?'

Sherlock turned again. 'John?'

John started. 'Sir?'

'What do you think? Why might a host scratch a young ward's name into the floorboards?'

'I dunno, sir.' But he answered anyway, proving to Sherlock, once again, that he might have some insight into a world the rest of them would rather not examine. 'Maybe . . .'

'Go on.'

But John was hesitant, thoughtful. 'Mrs Wilson called her Rachel? That is her name?'

Ignoring the impatient sigh from Lestrade and the rolled eyes from other officers and what seemed to them to be a redundant and unnecessary inquiry from an idiot, Sherlock nodded soberly; he could see where John was going with this before he even asked.

'Is it a good name?'

'It's a very good name,' said Sherlock.

'Then . . . maybe Mrs Wilson cared for her. Worried for her. Wanted to make sure Rachel was looked after.'

'Of course she'd be looked after,' said Lestrade. 'She's still got Mr Wilson!'

John's eyes flicked to Lestrade, then down, a little cowed. But he answered: 'Sometimes, sir, forgive me, but sometimes a man alone isn't the best host for little girls. Sir.'

'Why shouldn't he be?' Lestrade snapped. He turned partly away and ran a hand through his hair in agitation. Sherlock narrowed his eyes at the reaction, but before he could interrogate him, Lestrade continued, 'Look, that's . . . not really our division, now, is it? We deal with murders, not ward issues.'

'Sherlock, is your bell not working?'

Mrs Hudson suddenly appeared in at the door. She looked alarmed to see so many policemen swarming the flat.

'What?' said Sherlock, distracted and annoyed.

'It's just, your taxi's here. What's this? What's going on?'

'It's a drugs bust, Mrs Hudson,' said Lestrade glibly.

Her eyes went wide, and she crossed the room to Sherlock, taking his hand to pull his ear close to her mouth. 'They're just herbal soothers! For my hip!'

Meanwhile, Lestrade had turned to John. 'I think it'd be best if you stayed in your room the rest of the night. Mm?'

'Nope!' Sherlock pulled away from Mrs Hudson and inserted himself between Lestrade and John. 'Are you quite finished here? You already found what you came for.' He thrust one finger downward at the pink suitcase.

'Playtime is over, Sherlock. Send him to bed.'

'Sherlock, the taxi?'

'I didn't order a taxi!' To Lestrade, 'I'll thank you not to boss around my ward, in my flat.'

'I think these are fingers!' cried one aghast officer with his head in the open fridge.

'Is this illicit?' said another, holding out a plastic baggie to her companion.

'No, it's oolong.'

'Maybe I wouldn't have to,' said Lestrade, 'if you'd look after him properly. I'm mean, Jesus, Sherlock, taking him to a murder scene!'

'Sir, I can wait upstairs,' John volunteered.

'Good idea, very sensible,' Lestrade said.

'Or tell the driver you've cancelled,' said John.

'What's oolong?'

Laughter from the kitchen.

'He doesn't answer to you, you nit,' Sherlock growled. 'John, stay with me . . .'

At that very moment, his phone lit up in his hand. An incoming text from Unknown:

Come with me.

The answer came in a rush. Who do we trust, even though we don't know them? Who passes unnoticed wherever they go? Who hunts in the middle of a crowd?

He rotated slowly, toward the door, just in time to see a stranger—an old man in a grey cardigan and flat cap—holding a pink mobile. Around his neck hung a lanyard for the London Black Cab company. Then the old man, without even meeting Sherlock's eye, slid the phone into the pocket of his cardigan and turned back toward the stairs. Amid all the commotion, no one else noticed him.

As though in a trance, Sherlock followed him.

'Oi, where are you off to?' Lestrade barked.

'A minute,' said Sherlock as he left them all behind.

Was it really so simple? Was the man really so obvious while simultaneously being so completely camouflaged? Sherlock felt like an idiot for not having spotted it sooner. Everyone trusted a cabbie. A cabbie could take a victim anywhere. But why? And how had he got them to get out of the taxi, walk to their deaths in a secluded place, and swallow strychnine? He had to know. If Lestrade interfered now, Sherlock would likely be left out of the interrogation altogether. This would show him.

The taxi lingered at the kerb. Leaning against it, the serial killer sized Sherlock up and said with total nonchalance, 'Taxi for Sherlock Holmes.'

He carried a thick cockney accent behind yellowing, uneven teeth. But though everything about him spoke working class, his eyes were sharp, incisive, even daring behind square-rimmed glasses.

'I didn't order a taxi,' Sherlock said, not sure whether he should let on, yet, that he knew exactly who stood before him.

'I beg to differ. You sent me your address and everything. Not so clever, Mr Holmes, inviting a serial killer to your front door.'

Sherlock smirked. 'Is this a confession? Not so clever of you, showing up. I have a flat full of coppers, just upstairs, who would love to make your acquaintance.'

The man was unfazed. 'Oh sure, go get them. I don't mind, honest I don't. And I tell you what. I'll even come quietly, as they say. But I don't think you're going to go do that.'

'Why wouldn't I?'

'I didn't kill no one. I met some lovely people, we had a nice little chat, and they killed themselves. And if you take me in now, that's as much as I'll ever say. You'll never know exactly what it is I said to any of them. Not one word.'

Sherlock was galled at the thought of not knowing, but he couldn't show it. Instead, he shrugged. 'No one else will die though. I believe they call that a result.'

'But you won't ever understand how they died. And not knowing? Well, that will just eat away at you, innit? You're Sherlock Holmes, but even you can't deduce what it is I said.'

Dammit, Sherlock thought. He's provoking me, and it's working. 'And if I wanted to understand . . .'

The cabbie opened the back door. 'I'll show you. Let me take you for a ride. Both of you.'

Both?

Sherlock whirled and saw John standing behind him, just outside the door.

'John!' he cried in dismay. 'What the hell?!'

John stiffened, looking chastised. Glancing briefly at the cabbie, then back at his host, he asked shyly, 'Not good?'

'Bit not good, yeah,' Sherlock muttered. Bit not good at all. He was face to face with the killer they had been chasing, and he didn't know what would happen next. Only now did he realise his error ('John, stay with me . . .'), but it was best that he do this next bit on his own. It wouldn't do to put John in danger. 'Go back inside.'

'I'm afraid not, Mr Holmes,' said the cabbie. 'It won't do to have a witness. Our fun is just beginning. So he comes, too.' Discreetly, he lifted the grey cardigan just enough above his waistline to reveal the grip of a black pistol tucked into the front of his shirt. Shit.

'You wouldn't,' Sherlock reasoned. 'I told you, the police are just upstairs.'

'And four people are already dead. You think I wouldn't take out two more before they had a chance to get to me?'

Sherlock calculated his chances: the man was old and might not be very quick with the draw. In fact, Sherlock wagered he stood a fairly good chance of disarming him if he lunged unexpectedly. But on the off chance that the cabbie was quick, Sherlock couldn't risk John getting shot for the second time in his life. He stood a better chance of outwitting the man.

'John, get in the taxi,' he said, unable to keep the anger from colouring his tone.

'Sorry, sir,' said John as he hastened to obey.

Before following in after him, Sherlock turned his hardest glare on the cabbie. The cabbie returned only a haughty smirk. Then he pulled open the driver's side door, started up the engine, and they left Baker Street behind.

'Where are you taking us?' Sherlock asked. He spoke now in measured tones, mostly for the sake of his ward, who sat very rigidly with his hands on his knees, staring straight ahead, jaw locked and nostrils flaring. Though relatively composed, Sherlock could sense his anxiety.

'Patience, Mr Holmes,' said the cabbie. 'I shouldn't like to spoil the surprise.'

Sherlock spotted a black pen in the seat pocket in front of him, and a stack of business cards in a tray. Surreptitiously, he removed both, but given that he was sat directly behind the driver's seat, the cabbie didn't notice. He softly clicked the pen as he said, 'Is this what you do, then? Scout the city for a good place for a murder?' He flipped the card reading Jeff Hope, London Black Cab Co, and pressed the pen to the blank side, where he began to write.

'You see, no one thinks about the cabbie,' said Mr Hope. 'Invisible, you are. Just the back of a head. Proper advantage for a serial killer. I'm surprised more of us don't branch out. After all, we all know a nice, quiet place for a murder.'

Sherlock saw rather than heard the hitch in John's breath. He finished his scribbling and furtively passed the card to John, laying it upon his knee for him to read: Trust me. There's no danger. I know what I'm doing.

John pinched the card, glanced down, but looked even more alarmed when his head snapped back up. He looked at Sherlock and started shaking his head. Not quite the reaction Sherlock had been going for.

'How did you choose them, then?' Sherlock asked, thinking it best to keep a conversation flowing. 'Sir Patterson and the rest?'

'Enough chatter. I like it quiet when I drive.'

It was a tense twenty minutes in the back of the taxi. For the most part, John was perfectly still, still holding the business card between pinched fingers, but sometimes touching his identifying bracelets, as though anxious they might suddenly light up and cause them trouble. Sherlock wanted to squeeze his hand and calm him, but his written message hadn't been well received, so he doubted physically grabbing John would prove any more reassuring. Instead, he focused his attention on Hope, taking note of the smudge of shaving cream behind his left ear and the picture of two children on the dash, the mother cropped away.

At last, to Sherlock's surprise, the car pulled into the car park of Kerr-Roland Further Education College. He had been expecting, perhaps, a multi-storey or abandoned warehouse, given the location of the other victims, not a building in regular daily use.

'It's open. The cleaners are in,' said Mr Hope as he got out of the taxi. Sherlock and John followed.

'And what, you just stroll in and hope your victims follow?'

Outside the view of any possible witnesses or police, Hope finally pulled out the gun. When he saw it, Sherlock wanted to laugh. It was a fake! Though he didn't own one himself, he wasn't an idiot, and he knew how to spot a fake weapon. It was a fairly good replica, but a fake all the same. Oh, how he would love to shove it in Hope's face, haha! But with the danger to John or himself removed, he wanted to see this through, so withholding his cat-like grin, Sherlock instead just rolled his eyes and said, 'Dull.'

'Don't worry. It gets better. Off you go, then. The small one in front, there you are.'

Hope marched them both into the building, which was unlocked, just as the cabbie had said. They passed down a long, dark hallway, and finally into a large classroom with long lab tables. Hope waved his pistol and indicated that Sherlock and John take a seat in one of the plastic chairs, while he situated himself on the other side. And it was only then that Hope became properly observant. He started laughing.

'What's so funny?' asked Sherlock.

'Him!' said Mr Hope. 'He's a ward, innit? I seen the bracelets. You brought your bloody ward!' And he laughed some more. 'Don't think he'll even count against me. Five murders, then, and one squished cockroach.'

'Four murders,' Sherlock snapped, 'one arrest, and John and I toast the evening with a bottle of red wine.'

The movement was subtle, but John, who sat with his fingers interlaced in his lap, tried to manoeuver the fabric of his jacket to hide the bracelets, as though it made any difference anymore.

'Get on with it, then,' Sherlock continued. 'What's your grand trick?'

Still chuckling, Hope set the gun to the side of the table, far out of reach of Sherlock, and went for his pocket instead. From there, he extracted a single, clear vial, containing a single white pill, and placed it in the centre of the table.

Sherlock was unimpressed. 'So? You force them to swallow that pill at point of gun, do you? I thought you were clever.'

'I'm not finished,' said the cabbie. And from his other pocket, he pulled a second vial, identical to the first, and also containing a single white pill. This he placed beside the first and gave Sherlock a significant look, eyes flicking only briefly to John, then back again.

'And?'

'It's a game, Mr Holmes. Need I explain you the rules? There's a good bottle and a bad bottle. Your choice. You pick the pill from the good bottle, you live. You pick the pill from the bad bottle, you die. Shall we play?'

'Play what?' Sherlock scoffed. 'Games require skill, strategy. This is nothing more than roulette: a fifty-fifty chance!'

'I've played four times, and I'm still alive. It's not chance, Mr Holmes. It's chess. One move, one survivor. And this—this—is the move.' Hope lifted a hand, which twitched once. Then he reached for the bottle on Sherlock's right and slid it across the table toward John. 'Did I just give you the good bottle or the bad bottle?'

'It's a fifty-fifty chance,' Sherlock repeated, annoyed.

'You're not playing the numbers, you're playing me! You're trying to get inside my head, like I'm inside yours. I know how people think. I know how people think I think. And I know how you think, Mr Holmes. The real question is, do you know how I think? Did I give you the poison or the placebo? Is it a bluff? Or a double bluff? Or a triple bluff?'

Sherlock let out a long sigh. He cast a glance to John, whose hands were tightly gripping his own knees now. He wasn't looking at the pills, but at Hope, his eyebrows pinched with worry, like he was trying to figure it out.

'What if I don't choose either?' He shrugged to show his indifference to this little scenario. 'John and I could just walk out of here.'

'You'll play the game, Mr Holmes,' said the cabbie, reaching for the pistol, 'or I'll just shoot you in the head.'

John's head snapped to Sherlock, alarm written all over his face.

'Funnily enough, no one's ever gone for that option.'

Sherlock smiled blithely. 'I'll take the gun, please.'

'Mr Holmes,' said John, softly but with great concern.

'Are you sure?' said Hope. 'Your ward seems distressed by the very thought.'

'The gun,' said Sherlock confidently, leaning forward with a great smirk.

Hope raised the gun, levelled it between Sherlock's eyes, and moved his finger to the trigger.

It happened suddenly. Just as the cabbie squeezed the trigger, John shot to his feet and knocked Sherlock clean out of his chair and onto the floor, leaving himself in the path of a bullet. But with a spring-loaded click, only a small flame burst out of the muzzle. John flinched violently, only to discover, at last, that the gun was fake.

'John!' Sherlock cried, aghast. He scrambled back to his feet, but whirled on John, who stood dumbfounded, staring at the flame, then down at his chest, as though he couldn't believe he was still whole.

Hope burst out laughing.

John looked up from his chest, stunned.

Sherlock grabbed his shoulders and turned him roughly to face him. 'John, you idiot! What the hell were you thinking!'

'I thought . . . I thought . . .'

'I knew the gun was fake. I knew it!' Adrenaline was shooting like a pinball through his veins. He didn't mean to shout, didn't mean to shake John, but now he couldn't help it. What could have possibly possessed John to do something so reckless, believing the gun was real? For all his brilliance, Sherlock couldn't make sense of it beyond the apparent fact that John had tried to kill himself. The thought upset him so much he was squeezing John's biceps painfully and shaking him as he shouted. 'I'm in control here, do you understand? I told you to trust me. So trust me! I know what I'm doing!'

'Then prove it,' said Hope, who had risen to his feet as well, charged by the new energy in the room. 'You think you're so clever. Prove it. Prove to your ward that you know which is the good bottle and which is the bad.'

Sherlock's head snapped back to the table and the bottles set upon the imaginary chess board.

'Go on,' Hope whispered. 'Prove it to him!'

Two bottles. But he wasn't playing a game of chance. Just like Hope said, it was chess, a battle of minds, and Sherlock had to win it, to prove to John that he was in absolute control. So think. Reason through it. What move had Hope made? Obvious. He was a man living close to death (cancer, maybe?), but he didn't fear it. He was the sort of man who would walk into a room full of coppers searching for him, casual as all hell, and snag two more victims. He was the kind of man who kept poisonous pills in the pocket closest to his heart. All told, he would happily keep the deadly poison near himself, and offer Sherlock the harmless one. He would believe that Sherlock would distrust the proffered pill and reach for the other. So it stood to reason—simply, logically—that the safe pill was the one pushed toward him from the start.

'The gun wasn't real,' said John softly.

'I know, John, settle down,' said Sherlock, at last releasing his bruising grip and turning toward the table, ready to play.

'No sir, Mr Holmes, sir. The gun wasn't real.'

Sherlock looked back, puzzled. 'I know,' he repeated, a little exasperated.

'So you don't have to play.' Anger flashed in John's eyes, but briefly, so briefly that Sherlock wasn't even sure what he saw. He'd never seen John angry before.

Caught off guard by the hardened expression on John's face, Sherlock blinked and asked stupidly, 'What?'

'He's holding a fake gun. You don't have to play. He can't make you. You're a free man, Mr Holmes. He can't make you.'

'Looks like you've got yourself a cabbage for a ward,' said Hope. 'And a chicken-livered one at that. Or is he right? Are you too stupid to outwit me?'

Sherlock winced. 'I've already figured it out, arsehole.'

'You know where the poison is?'

'Of course I do.'

'Then prove it. Let's take our medicine.'

'Please, Mr Holmes,' John pleaded.

'I can do this, John. I'll show you.' And he reached for the bottle nearest him.

But John snatched it up first, and backed away.

'John!'

'You're not stupid, sir, I know you're not. But taking this? Swallowing this? That's stupid.'

'But I'm right!' He was so keyed up, every nerve on edge, every synapse firing like crazy. If he didn't do something soon, if he backed away now, he thought he might just explode.

John was breathing hard, looking between the cabbie and his host with trepidation. 'Really?'

'Really!'

'You're really sure?' he challenged.

'Yes! Of course yes.'

'Then you won't mind me taking it instead.' And with that, John twisted the cap off the vial.

A white-hot panic, unlike any he had ever known, fired throughout Sherlock's body like lit petrol. 'No!' Sherlock cried. He lunged for John's arm to stop him, prepared to wrest it from his grip, slap it out of his hand. But John dodged his lunge and darted away, quicker than Sherlock expected of him, what with the dodgy leg. 'Goddammit, John!'

'If you are right, I'll be fine, won't I?' John argued as he tipped the pill into his open palm.

'Oh ho ho!' tittered Hope, excitedly. 'Let's find out then, roach. You and me.'

'I— I—'

Sherlock floundered. God, what if he was wrong? What if he had made a critical error in his calculations, and for it, John paid the price? If John swallowed that pill, he wouldn't wait to find out. He would wrestle the man to the floor and shove a finger down his throat, if it came to it, and force him to throw it up again. Because he wouldn't watch John die, he just wouldn't.

'I may be wrong,' he admitted. 'John, please. I may be wrong.'

John nodded, blinking rapidly. His whole body was trembling. 'Yeah, I think you may be.'

Once again, almost as if he had to remind himself that the cabbie was still in the room, Sherlock returned his attention to Hope, whose lips were contorted into a line of disapproval, even disgust.

'You let your ward make your decisions for you? Coward. You'll never know, then, will you? Whether you would have beat me.'

Sherlock scowled.

'Sir,' said John, softly, 'might we now call Mr Lestrade?'

His heartrate was slowing, and his mental faculties had ceased to whir. The thrill of the chase that had led them there, and threatened both their lives, was melting into cool reason and practicality. Maybe it wasn't such a bad thing.

'John,' he said mildly, 'put the pill back in the bottle. Screw the cap tight, and put it in your pocket. Then come help me tie him up. You're right. Let the police deal with him.'


The officers cuffed Jeff Hope and put him in the back of a police car. Sherlock watched him go through the window with a mixture of satisfaction and confusion. It had been a strange night.

'Good thing he didn't have a real gun,' said Lestrade, closing up his notepad. The two bottles of pills had been bagged as evidence (Sherlock made them note which was which so they wouldn't be confused during analysis), along with the lighter in the shape of a pistol. 'Might have had a night of multiple homicides, and I really do hate those.'

Sherlock grunted in acknowledgment. John was on the other side of the room in a chair, being seen to by Constable Donovan, who was crouched next to him. Seen to? What was she saying? Why was her hand resting on his knee? John didn't like being touched. She should get her damn hands off him.

'Sherlock, are you listening to me?'

'It's been a long night, inspector, and we've just caught you a murderer. I think John and I would quite like to go home now.'

Lestrade grunted. 'Fine. There may be follow-on questions, of course. We'll get Hope's statement, run analysis, tie him to each of the murders—'

'Yes, I look forward to the court case,' he said, stepping away to collect John.

'But Sherlock, you can't do this again.'

Sherlock rocked back. 'Do what?'

'Bring him.'

'John? Why the hell not?'

'At best, it's grossly inappropriate. He's a ward, Sherlock, not your playmate. He has no business being involved in police work. You might even be cited for ward endangerment.'

'Endangerment! He was perfectly safe! And frankly damn useful. He saved my life tonight.'

'I'm telling you, Sherlock, you can't. If you insist on it, I'll stop bringing you on altogether, hear me? This isn't a bluff.'

Sherlock sneered. 'Then good luck solving your cases on your own, you pillock.' And he stormed away, Lestrade calling his name with weary vexation. He approached John and Donovan like the reckoning and said gruffly, 'We're leaving.'

John rose quickly, but Donovan was slower, smoother, and when she had reached her full height, she regarded Sherlock with her characteristic look of disdain. ''Nother one cracked, is it?' she said.

He anticipated she was about to go further, so, to head off her second scathing remark, he grabbed John by the arm, said a hasty, 'That's how I roll,' and strode away, John in tow.

Once they were finally cleared of the coppers and back on the street, Sherlock realised, again, that he was holding John too tightly. He dropped his arm and slowed his pace, and for a couple streets more, they walked on in silence while Sherlock made a half-hearted effort to look for a free taxi. Which was the last thing he wanted to do. He should have made Lestrade give them a ride home.

'I'm sorry, John,' he said, surprising even himself, speaking with half-formed thoughts. 'Tonight was . . . tonight was . . .'

'I'm glad you're okay, sir.'

'Me?' Sherlock laughed shortly. 'What you did, back there. It was . . . good. Very good. John, you may very well have saved my life tonight.'

John looked uncertain how to respond, or even whether he ought to. So after a bit of awkward silence, he simply said, 'Yes sir.'

Sherlock laughed again, this time with less restraint, more pleasure. 'I might have got it right, though.'

'No sir, I don't think you did.'

Sherlock stopped short, quite taken aback. A few steps later, John noticed and stopped, too. They stood facing each other. 'Don't you?'

'He gave you the bad bottle,' said John, simply.

'Might not have done.'

'But he did, sir.'

'How do you know?'

John pursed his lips thoughtfully. 'He looked at me, just before he made his move.'

'So?' But he was reviewing the play-by-play in his memory, and yes, there had been a moment, just before Hope had slid the bottle across the table, just a hair of a moment: Hope had glared at John.

'He hates wards, sir,' John said as a matter-of-fact.

Sherlock narrowed his eyes, equally disturbed and intrigued by what John was saying. What if John was right, and his presence there had compromised Jeff Hope's ability to think, resulting in emotional, not logical, reasoning? What if, in another scenario, had it been just the two of them, Sherlock would have been right in thinking Hope would keep the poison closer to himself, but it was John—John, the wild card—that had disrupted his streak, had awakened his prejudice, and subconsciously or otherwise, he had pushed the poison closer to the creature he despised? And damn, Sherlock had almost fallen victim to it.

'Why did you jump in front of the gun, John?'

John looked abashed. 'You said, sir,' he said slowly, 'let's not make it nineteen.'

If nothing else had done it that night, these words at last humbled him. If Sherlock had died, John would have ended up back in the system. Another pound, maybe another host. Number nineteen. This wasn't just about saving Sherlock's life. In some sad and warped way, it was about saving his own.

'That's a decision I wish you had never had to make.'

'Sorry, sir. I know you would rather I hadn't come.'

'To the contrary.' He waited until John's eyes lifted, and they were looking at each other properly. Sherlock smiled. 'You proved invaluable. And what's more, I've never had such fun on a case.'

John eyes brightened; the corner of his mouth turned up. 'Really?'

'I never lie.' Nothing—neither finding the pink suitcase, nor watching Jeff Hope get marched away in handcuffs—gave him more satisfaction than the look on John's face at this very moment. 'Dinner?'

'Starving, sir.'

With a motion of his head, they continued walking, but from time to time, Sherlock cast a sideways glance at John, who was fighting it, but couldn't stop himself from smiling.