After another hour of sitting looking at the grey tiled walls of his cell, Sherlock heard two sets of footsteps in the corridor and the jangle of keys. He recognised John by his walking pace and gait well before the door swung open, bringing both him and Charlie into view.

A one-second glance told Sherlock that he was not going anywhere immediately, though John had tried.

"Hi. Brought you something," he said awkwardly, placing a plastic bag stacked with steamed-up rectangular containers onto the bench seat beside Sherlock, who barely glanced down at it. Chinese food.

"I'm stuck in a holding cell, and you brought me dinner?"

"Best I could do, Sherlock. Sorry. I even called Mycroft for you, asked him if he could make a few phone calls and sort this out. I won't tell you what he said... oh, fine, here." He put Charlie on Sherlock's knee.

Sherlock sighed heavily.

"Anyway," John continued. "You're stuck in here for the night." He handed him a pair of chopsticks wrapped in white printed paper. Then, as if it had just struck his mind, went to his pocket again and drew out Sherlock's phone. "Merivale said you can have this back," he said. "I told her you might need it. Might've hinted that Mycroft will go on the warpath if he can't contact you in a hurry."

"It's likely." Sherlock snatched at it and peered at the display. At 48%, the battery mightn't last the night, but it was better than not having it at all. "Oh," he said vaguely, not glancing up from the display. "I think you might want to do something with the cat, or something…"

"You mean, like feed her?"

"Yes. That." Sherlock waved his hand dismissively.

"Already done. Don't worry about her... and that's your own food, Sherlock." He pointed. "Just so you know."

Sherlock riffed the top off the first container and, with expert precision, poked at the contents with his chopsticks and started shoving Schezuan Prawns into his mouth. Immediately, Charlie grabbed for it. "Mine," she said in a little voice.

John laughed. "That's a new one," he said. "What the hell are you teaching her, Sherlock? Looking forward to 'bored' and 'now' next. No, Charlotte. I know you're probably starving by now, but definitely not yours." He turned his attention back to Sherlock. "So what do you want me to do now?"

"I want you to take yourself – and your gun – over and stay with Greg's family tonight," Sherlock said. The spices in his mouth suddenly kicked up a gear, and he coughed. "Just in case…"

"Just in case of what? You seriously don't think the murderer would be stupid enough to target Greg and his family? It's pretty clear we're onto them."

Sherlock shook his head. "I hate this," he said, "but I have no idea what they're going to do next."

"Well, I can tell you what Greg's going to be doing next – driving through every street in London, trying to guess where you've put Matthew. He probably won't be home at all tonight. Sherlock, if you just told him –"

Sherlock shot him a look.

"Then tell me," John said.

"And what will you do when Greg asks you if you know where Matthew is?"

John hesitated for a second. "I wouldn't tell him," he finally said.

"Your face would, and the rest of you would follow. You're a terrible liar."

"Okay." John sighed. "So please tell me he's at least got money? Food?"

Sherlock considered this. He had told Matthew where to find the emergency supply of cash in the bolt hole – all ten pounds of it – in the refrigerator door. It wouldn't last long, but at least some of the Network knew what was going on by now and would be able to help, provided Matthew got up enough nerve to actually ask for it.

"Yes," he said. "He does."

~~o0o~~

John's insistence on bringing Molly and Charlie with him to Greg's place wasn't entirely motivated by their comfort and safety. Both were favourites with Greg, and as fumed-up as he was over Sherlock's apparent betrayal, he was unlikely to turn them away. He waited until Molly had taken Charlie upstairs to change her before even opening his mouth.

"I suppose you think I'm being unreasonable," he said over his shoulder at no-one specifically as he stormed about the kitchen, opening and closing cupboards as if looking for something.

"No," John said. "If he wouldn't tell me where Charlie was, I'd probably deck him."

"But getting mad about it isn't helping Matty, Dad," Hayley tried. "Or anyone, really."

Beside her, Jake reached out and touched her arm. She turned and looked up at him quizzically, and he shook his head a little.

"And anyway, Mel, what's going on with you?" Lestrade suddenly turned to her accusingly. "You're a forensic psychologist, and you haven't said much about the killer. What are we meant to be looking for?"

Melissa thought for a second, then blew out a breath through her lips. "I really can't give you an accurate profile off the top of my head," she said, folding her arms. "And it's hard when it gets personal. But I think the police already know the basics, anyway. This is a young man's crime. Probably no older than thirty-five, forty at the most. Average intelligence."

"Average intelligence, who's based his crimes around the complete works of William bloody Shakespeare?"

"But he hasn't, has he?" John pointed out. "I noticed that about Thompson's death. It all seemed pretty legit, until Molly called. She told me he drowned in water, not wine."

"And what's that mean?"

"It means the killer's not killing ritually, according to Shakespeare," Melissa said. "He's just propping the victims up afterward to look like he is. Playing a game, not fulfilling a psychotic impulse. It's a totally different motivation. With a totally different psychological profile. Most serial killers, in the strictest sense of the word, pick their victims at opportunity – not randomly. They pick out the vulnerable ones. But this guy is targeting specific people. That's a vendetta."

"A vendetta about what?"

"Did you never chat with Matthew about your job?" John tried.

Lestrade groaned. "No," he said testily. "I've already told Merivale that. I don't discuss work at home."

"Yeah, well, Sherlock thinks he knew something, anyway," John said. "And I'm thinking it's probably about a case, but I can't be sure."

"Neither can I, and I can't bloody ask him because he's probably holed up under a bridge somewhere."

John and Melissa looked at each other in silence for a second or two, just as Molly appeared in the doorway with Charlie.

"This novel of his," John finally said. "It's a crime novel, right? Do you have a copy I could get my hands on?"

"Um." Lestrade swiped at his forehead for a second, thinking. "There was a copy on his computer, but that's with the tech team. But I'm pretty sure he also had a hard copy in his room somewhere. I could go find it." He frowned. "You think it'd help?"

John shrugged. "It can't hurt, can it?"

It was almost completely dark in his cell when Sherlock slowly woke. Only the exit sign over the door gave off a dull green glow. He blinked and then realised what had woken him - June Merivale, still in her conservative blue power-suit and leather shoes, was sitting on the bench near his feet. He started, but she almost smiled at him. "You sleep like a baby, Mr. Holmes," she said.

Sherlock sat up, unsure of how to react to this. "How long have you been there?" he asked.

"Only a couple of minutes."

Sherlock pressed the display on his watch, and it lit up for a second, showing it was shortly before two in the morning. "And are you visiting me for any particular reason?" He drew his coat around himself grouchily. A couple of minutes? That was long enough to strangle someone in their sleep.

"Greg Lestrade's daughter got a phone call from someone when she was outside the British Museum this afternoon," Merivale said. "We've just received the CCTV footage from the time of the call, and I'd like it if you had a look at something for me."

Sherlock gave a snort of contempt. "For you?"

"For Greg, then, if you like."

The shot told. Sherlock took a deep breath and rubbed his eyes, then gave his cheeks a few sharp slaps, trying to wake himself up. The slats he'd been sleeping on weren't exactly comfortable, even given that his old back injury still ached a little when tested. "Where?" he asked.

Merivale got up, and, not bothering to put on his coat or shoes, he followed her out down the corridor and through the security doors into the back offices of the criminal investigation division. A handful of detectives were huddled together around a dated television box.

"Good morning, Sleeping Beauty," Alan Peters said over his shoulder. Sherlock paused, still half-asleep and trying to work out if he was being menacing or simply a little sarcastic. Before he could properly make up his mind, Peters slid a steaming-hot cup across the desk toward him. "Coffee," he said.

Sherlock took a hesitant sip, wondering if he was missing something about these Ordinary People transactions. But the coffee tasted completely ordinary, though it was without sugar and bitter.

"I know," another detective, the one Sherlock knew as Matheson, said as he smirked a little at Peters. "Welcome to Team Merivale, Holmes. The coffee is awful, but we're all really, really awake."

"Right," Merivale said, ignoring Matheson and picking up the remote control of the TV. "Hayley told her father - who told me - that when she was on the phone to whoever it was who called, she heard a bus take off from the kerb, both in her free ear and down the phone line. So the caller was in the close vicinity. When the call came up as from the payphone nearby, I got this. We don't have a lot to go on, but it's something." She pressed play, then gestured to a figure in the grainy footage with one finger. "There's Hayley Lestrade as she comes down the steps. She's on the phone already, but it seems she was on the phone to Detective Constable Dyer, who'd been making some enquiries I'm going to have to follow up about."

Sherlock snorted into his cup of coffee, wondering if anyone outside of Lestrade's regular team knew that Hayley Lestrade was doing a lot more than talking on the phone with Constable Dyer. Probably not. It wasn't automatically a breach of conduct for Greg to be supervising someone who was sleeping with his daughter, but it would certainly raise issues about a conflict of interest.

"And here you can see the phone box in question. The caller must have crossed the street first, judging from where they enter the frame here." Merivale pointed. Since Sherlock had already noted the caller's approach and didn't need it spelled out, he instead focused on something he'd been too tired to notice about Inspector Merivale when she'd woken him – her short, utilitarian fingernails were painted a deep plum shade. Extravagance, for a woman of her age and profession.

Sherlock had sometimes wondered why, if London had to have about fifty CCTV cameras for every one of its residents, they had to have such poor visuals and even worse sound. To the untrained eye, the dark figure who Merivale played fifteen times walking into frame, sliding into a phone box on the top left-hand side of the screen, and picking up the receiver ten seconds before Hayley Lestrade did, was just a darkly-dressed enigma.

Fortunately, Sherlock Holmes was not the untrained eye, and June Merivale, while she may have been in his estimation completely dull-witted and unfairly prejudiced against anyone who wasn't, realised it. It was he who had asked her to play the nine seconds of footage, over and over again.

"Right," she said at last, putting the remote control down as if passively refusing to play it one more time. "So we're looking for a man – "

"Woman," Sherlock corrected her quietly.

"Sorry, what?"

"Don't be fooled by the clothing," Sherlock said, pointing to the dark figure frozen on the monitor. "The clothes are what ordinary people remember, so they can be used to create false memories. This person's height and walking pace are both suggestive of a female, and their gait and posture proves it absolutely."

"Does it?"

"There are distinct differences in the way men and women walk. It's not entirely cultural conditioning; biologically, their hips and pelvises are angled differently. That's a woman. I'm certain."

"Well, if it's a woman," Merivale said thoughfully, "any ideas of who it is?"

"Play it again."

Before Merivale could huff Peters fumbled for the remote control and played the grainy footage again while Sherlock peered at it.

"Given her dress and height, I think you're looking for a teenager." Sherlock straightened up. "Call Caitlin Trent in for an interview," he said. "I think she has some explaining to do."

Four chapters into Matthew's novel, Death Watch, it was pretty obvious that Greg had never picked it up in his life. No matter what he told his son.

John, camped on the downstairs sofa while Molly and Charlie took Matthew's vacant bed, was riveted almost immediately - though maybe not for the same reason as the casual reader would be. The whole thing was a loving tribute to Matthew's secret hero: Sherlock Holmes.

For his lead detective was Sherlock, even though Matthew had managed to name him something even more absurd than Sherlock Holmes: Benedict Cumberbatch. Otherwise, details were strikingly similar. Tall, dark, handsome, well-dressed. Brilliant mind. Little tact. Penchant for being a drama queen. A sidekick, even, whom John was pleased to discover was rational and intelligent, and so far doing quite a lot to assist the hero in his pursuit of a serial poisoner.

But the tension in the house, even with everyone else in bed upstairs, wasn't conducive to a pleasure read. Shortly past two o'clock, John was close to dozing off altogether when he heard the light trill of Molly's mobile phone ringing upstairs. Several minutes later he heard shuffling in the upstairs passage and then Molly tip-toed down the stairs.

"Are you awake?" she whispered to him.

"Yeah." He sat up. "What was that about?"

"That was Philip. He's still waiting on some proofs and can't leave them, but he said he's about falling over exhausted and needs some help. I said I could go and keep an eye on things for a few hours."

"… Philip…?"

"Yes, you know, Philip Anderson?"

John blinked. Christ, had Anderson really been in the lab at New Scotland Yard for the last eighteen hours straight?

"I suppose he was going to tell you anyway," Molly said, "but he was saying he hasn't found any of Matthew's fingerprints in any of the samples he's checked, and nothing in the DNA profiles he's run to suggest Matthew was ever in the house. But the proper tests with full profiles can take weeks to come back."

"Great," John muttered, thinking back to what Sherlock had said about how quickly the killer was working. A few weeks would be long enough to kill off half of Scotland Yard.

"I'll text you when I get there and let you know what's going on," Molly offered.

"Sure, thanks." He reached over to the coffee table and swiped up his car keys, holding them out to her. "And Charlie?"

"Fast asleep - I'm surprised the phone didn't wake her, but she's had such a big day. You should probably want to go up to her. If she wakes up and finds herself on her own, she may get scared."

"Or fall off the bed," he said, remembering an unpleasant incident two weeks before when Charlie had done just that and nearly given both her parents the fright of their lives. He stood up and leaned over the coffee table to kiss Molly's cheek. "Don't tire yourself out too much, Lolly."

"No. Promise I'll be back soon."

She slipped her shoes on in the front entry and gingerly opened the heavy front door, trying not to make too much noise with it. It stuck, and then swung open with a sharp creak. She flinched, then went through and shut it behind herself. He listened to her muffled footfalls on the front steps.

Something smashed.

John heard a muffled little cry from Molly. In half a second he'd thrown the front door open and was beside her at the foot of the steps.

"What?" he demanded, trying to see for himself in the dim light of the street lamp. But before Molly could explain it, he saw. Greg's car was parked in the driveway, and slivers of glass were scattered around the back panel window. In the shadows beyond, he saw someone in a dark hoodie running up the street.

"Hey!" John took off after them. But he was barefoot, and they had a good head start on him, never once even glancing back. It was only when they disappeared into a laneway that led to a nearby park that he remembered he'd left Molly standing on her own at the bottom of the steps. By the time he turned back she was walking quickly toward him.

"What the hell just happened?" he blurted out, glancing up as a light flickered on in one of the upstairs bedrooms. Well, he'd woken someone, anyway.

He heard the distant thud of feet on the staircase and Greg appeared on the front step, still fastening his trousers with one hand. "John?"

Upstairs, Charlie started to wail, but John barely registered the sound. He had just seen the hessian bag that the intruder had thrown onto the front seat of Greg's car. It seemed empty, but on it was pinned another note. No Shakespeare this time.

Help her.