Greg's not dead. Don't tell anyone - SH

Today 8:42am

And by that, I mean anyone. Delete both my messages - SH

Today 8:43am

Molly had been in the lift, on her way back from a canteen run for breakfast and juggling hot tea and a bacon sandwich, when her phone had bleeped twice in short succession. She'd pulled it out of her pocket immediately - it might be John, about Charlie. Then she let the lift doors close on her again as she stood reading both messages over.

Are you still in custody?

Today 8:47am

Technically, yes. - SH

Today 8:47am

Molly took a deep breath. Then she deleted all of Sherlock's messages from her inbox and, to make doubly sure, deleted her own from the outbox as well. The lift doors opened and she shut them again, then mashed her palm against the ground-floor button to stop the compartment from going anywhere.

There was a reason Sherlock's bolt-hole was so close to where Molly worked.

There was at least one other, she knew, much closer to New Scotland Yard headquarters, but she didn't know where that one was. He used that one for when he needed Greg to have unrestricted access to it, so there was no chance he'd taken Matthew there. She knew that there were more places, maybe half a dozen more, and she had no way of telling for sure which one Sherlock had taken Matthew to. But had there been anything… implied… in Sherlock's texts? She'd go and see. If Matthew wasn't at the Cock Lane bedsit, then the matter was out of her hands.

None of the tests Anderson had set up were at a stage where they needed to be interfered with for at least an hour, and Anderson himself was in one of the heaviest sleeps she'd ever seen on the sofa in the vestibule. He hadn't moved in hours. It was too bad that she wasn't even working at Barts that morning, and she wondered if Sherlock even knew that, since he'd been "technically" in custody all night. But the distance was no matter - a short bus trip and then a brisk walk she sorely needed to perk up after being in the fluorescent-lit tech lab at New Scotland Yard headquarters almost all night. The rain had broken up in the early hours, but low-hanging, grey clouds scudded across the morning sky, and as she stepped into Snow Hill, the pavements shone in the low orange sunlight.

On reaching the right door, she tapped on the door lightly with her knuckles. There was no reply, and she gave a more forceful rap. This time she heard a furtive squeak, as if someone had just risen from a bed or an armchair.

"Matthew," she whispered into the crack of the door-frame. "It's Molly. Could you open the door, please?"

But behind the door, all was stillness. Matthew was close behind it - so close that she could almost hear the whisp of his breath, the thud of his heart. Molly set the shopping bag down on the step and lay her cheek against the door, listening for a few seconds to those slight breaths and the hum of the refrigerator behind them. Was he hurt? Was he crying? She didn't know if it was normal for a boy his age to be crying behind there, but if Charlie…

Just don't check this morning's news. Please. Despite Sherlock's texts, the early news bulletin reporting Greg's death had been harrowing to watch, bringing back a flood of painful memories from when the reported death had been Sherlock's. She was certain that Sherlock wouldn't ever make the mistake again of drawing her into a secret and leaving John out of it. But did Melissa think Greg had died, too?

"Matthew," she said. "Sherlock's with the police. So… he asked me to come and make sure you were all right."

No answer.

"I thought…" she struggled. "I thought you might need some things. I'm going to leave them on the doorstep for you, okay? Just… um."

Still no answer.

"I'll be at work tomorrow," she offered. "I'll come over again when I'm finished. Six o'clock. You might want to talk to me then."

Unlikely, but it was all she could do to try. Rustling the shopping bag as if to remind Matthew it was there, she turned on one heel and quickly walked away.

It was only once she'd returned to the NSY lab that Molly remembered she had no electronic pass to get back into it. After nearly five minutes of increasingly desperate knocking on the door, she'd succeeded in waking Anderson. He blearily got up and let her in.

"Something wrong with your pass?" he asked sleepily, heaving sour, hot breath into her face.

"I don't have one," she faltered, taking a step back. "I'm so sorry. I forgot. I'm so used to having one where I work…"

But Anderson did not seem interested in her long-winded explanation of why she'd woken him to let her in. He shrugged her off, curled back up on the sofa and quickly started snoring again.

And then it hit Molly like a freight train.

Shaking with a surge of nerves, she enclosed herself into the main lab - checking that everything was still humming away and hadn't self-destructed - then pulled her phone out and ducked behind the counter, as if she were being ambushed. In a few seconds, John picked up.

"Just so we're being honest," she blurted out, "I know where Matthew is. Please don't ask me to tell you."

Since Sherlock's return, Molly had vowed she'd never keep a secret from John again - provided he asked her to disclose it. Once or twice since, though, she'd compromised with I'll tell you if you ask me. Please don't ask me.

John was silent on the line for a few seconds. "Okay," he finally said. "Ask no secrets, be told no lies. Got it. Is he okay?"

"I don't know… I… I don't know. I left him some money and food and toothpaste and… John, there's something I need to talk to you about."

"Sure, talk to me." John sounded like he was stifling a yawn into his hand.

"How do we know Anderson was in the lab all that time?"

There was a dull thud on the line, as if John had either opened or closed a door. "Sorry," he said, "what?"

"Well, it's just he said he'd been in the lab for eighteen hours straight when he called me. I suppose he could have been. But if he was working on his own, he might not have been. He might have… been able to come in and out without being seen."

"There's got to be security footage of it, though, right? I mean, it's New Scotland Yard-"

She nodded, temporarily forgetting that he couldn't see her. "And there's also his electronic pass," she said. "He could get out of the lab without it - you know, in case there was a fire or something - but not back in again. Hospital security should be able to tell us whether he was really here the whole time…" She bit her lip. "It probably doesn't mean anything," she fumbled. "I mean, it doesn't mean he was involved in anything that's happened.. He probably wasn't. He's… I just thought. You know."

"Molly," John said. "Is he still there with you?"

"He's asleep." She peeped through the vestibule doors out to where Anderson lay, rock-like. Was he asleep? His gaping maw and gurgling snores sounded almost like a parody of a man asleep, instead of a real one.

"All right," John said. "I'll let Sherlock and Greg know about the passes; see what they think. Can you hold on for…" He paused. "For half an hour, give or take? Merivale's got Caitlin Trent in for an interview at half-past nine, and wants Sherlock and me to be there for that." He paused. "For some reason."

Merivale reached for the little Tupperware container where pods of machine coffee were kept. Then, at the last second, her hand veered off and came to rest on the shiny lid of a canister instead. No. The little cow can have instant roast.

Caitlin Eleanor Trent, aged seventeen, was sitting in Interview Room Two. Room One was reserved for the most intractable, hardened interviewees. The windows were smaller and higher, and it contained little more than a table and two chairs, all bolted to the floor in case someone decided to throw them. But Room Two was more for witnesses, grieving families, and young ones. It was painted a manic shade of yellow and had wide, low sofas in red and blue. As a minor, Caitlin was accompanied by her stepfather, a shrivelled little man who had introduced himself as Robert Trent. Also in there with her, Sherlock Holmes and Dr. John Watson were waiting.

Despite news that morning of Lestrade's death, they'd both made it in as requested.

Other close colleagues of the late Greg Lestrade had proved unavailable for comment. Det. Constable Jacob Dyer's phone was off, and if that hadn't been enough to send Merivale into a rage, Det. Sergeant Sally Donovan had answered her phone and told her to fuck off. Her number was blocked - she knew, because she'd used Alan Peters's mobile to call back and Donovan had answered it and asked her if she had trouble understanding the words "fuck" and "off". And then she'd blocked Peters's number, too.

To her dismay, she was still so angry at Greg - Greg, who was a nice guy and a good detective, everyone had liked him, Greg who was dead - that she was close to breathing fire. What the hell was he thinking, opening the car door before Forensics got to it? He knew. He knew to never, ever…

No. She pushed those thoughts aside. Whatever Greg Lestrade thought he was doing poking around in the car, he was dead. Death wasn't a reasonable or expected outcome of opening your bloody car door. Greg was a victim. And you never blamed the victim.

"Need a hand?"

She whipped around, startled. But it was only John Watson, haggard under the fluorescent lights, standing in the tea-room doorway. His hands were tucked under his arms.

"Oh," she said. "Yes. Thanks." She handed him her own coffee and his, and picked up the cups she'd prepared for Sherlock, Robert and Caitlin. "Before we go in," she said, "you've had a look at her now. Definitely not our snake-charmer?"

John shook his head. "I mean, I only saw him for a second," he said. "It wasn't her, though."

"If she was wearing a hood-"

"Wasn't her."

"What about…" She put down her hot cups and led John out to the incident room, rifling through papers on the desk for half a minute. "What about him?" she asked, almost desperately, shoving an 8 x 12 photograph at John. He obligingly peered at it.

"Nope." He gave it back to her. "Definitely not him, either."

Merivale sighed as she took the photograph back and laid it in the middle of the pile. In any case, Edward Trent had no motive either, and he had an alibi, of sorts - his mother had said he had been with her all night, and there was no reason to think she was lying. Looking up, she saw John's gaze fixed on the nearby whiteboard. At six-thirty that morning, someone had added "Det. Greg Lestrade" to the list of victims on the left side of the board.

"I'm so sorry, John," she said, calling him by his first name for the first time.

"Yeah." John's face twitched. "Me too."

"Are you ready to do this?"

He nodded, and she led him back to Interview Room Two, swinging by the kitchenette on the way to gather up the coffees. Though, she reflected as she set one down in front of him, this was going to be the very last time she ever made Sherlock Holmes a cuppa. After the preliminaries of the interview were over with, and Caitlin had grunted that she understood what was happening, Merivale slapped a heavy morning newspaper down on the desk between them so hard that it almost bounced.

"Someone threw a live snake into Matthew's dad's car last night," she said. "An Egyptian Cobra. He didn't see it when he first got in, and it bit him."

She paused, trying to gauge the girl's reaction. Did she already know? Did she know what the next item of news would be? Her expression gave away nothing but curiosity. June Merivale considered herself to be a very good judge of character.

"Is… is he okay?" Caitlin finally ventured.

"No." Merivale shook her head. "He died, Caitlin. We had a call from the hospital just before six this morning. London hospitals don't have endless supplies of anti-venom for foreign snakes. By the time they'd located some and brought it in from another hospital, it was too late."

Caitlin's jaw dropped. "Oh, my God," she whispered. And there was something else Merivale noticed: a certain look of that-was-not-supposed-to-happen.

"Now the snake," she went on, "was stolen from a reptile collector named Prosser. And guess what we found? Just as a coincidence, his son Aidan goes to school with you."

Caitlin tilted her chin a little. "No," she said haughtily. "Aidan Prosser goes to school with Matthew. In between me and Ed. Along with, like, a hundred other people. I don't think I've even, like, said anything to him. I've heard his name in the bulletin and sometimes at assemblies. I think he might be on the football team or the cricket team, or some other stupid thing I don't care about. I don't know him."

Merivale shuffled the case files in front of her. "Never been to his house?"

"No."

"Did you know his dad had half-a-dozen poisonous snakes at his house?"

"Venomous," Sherlock suddenly interrupted.

Merivale blinked and turned to him. "… Sorry?"

"It's poisonous if you eat it. It's venomous if it bites you."

Merivale considered this for a few seconds before deciding on, "Kindly shut up, Sherlock."

The kindly was a concession to current circumstances, as well as keeping-the-status-quo. Sherlock struck her as the last man on earth who'd react well to being emotionally mollycoddled, even if he'd just lost someone who, for want of a better expression, could be called a close friend. But Sherlock barely reacted to the verbal finger-slapping. He was very quiet; barely there at all, mentally, or so it seemed to her. Shock? She considered this and then rejected it. Sherlock wasn't in shock. He'd withdrawn deeply into himself to think, not grieve. John Watson, on the other hand, seemed to Merivale to be the most unflappable person on earth. He was all business, except in odd moments where he'd solicit Sherlock with a glance or twist at his wedding ring.

"Caitlin?" she urged.

Caitlin groaned. "No, I didn't know his dad had all these stupid snakes at his house, because I don't know him."

"You're sure? We can check," John said.

"Check, then," she huffed. Then, under her breath, "idiot."

"Caitlin," Merivale said, before this could degenerate any further, even though John Watson's reaction to being called an idiot seemed to be part exasperation and part wry amusement. "Show me your arms."

"My what?" Caitlin echoed. She drew back in her chair slightly, lacing her fingers in and out of one another. At a glance, those fingers seemed undamaged.

Pull up your sleeves," Merivale said. Then, as an afterthought, "please."

"Is it even, like, legal for you to ask me to do this?" Caitlin rolled her eyes, fingers twitching at the cuff-buttons on her long-sleeved blouse. All three investigators had noted it: an oddly Puritan thing for a teenage girl to be wearing in August. But Caitlin drew back both sleeves without hesitation and lay her arms across the table for Merivale's perusal.

No scratches. No bruises. No lacerations.

Caitlin said, "Happy now?"

"I'd be a lot happier if you'd give me less mouth. The reason we brought you in today is to ask you about an incident the day before yesterday. Hayley Lestrade was out the front of the British Museum when she took a call that came from a phone box."

Caitlin shrugged. "Did she? That's nice."

"A nearby phone box. So close, actually, that you could be clearly seen in the CCTV footage making that call to her…"

Sherlock scoffed.

"Sherlock identified you," Merivale tacked on, determined to give credit where it was due. "And Hayley said you sat on the line for a few seconds and then hung up. Her father's now dead, Caitlin. You've got a lot of explaining to do. Why were you stalking and prank-calling Hayley Lestrade? Do you realise how suspicious this looks?"

Caitlin's bottom lip trembled slightly. "I…" She splayed her palms out on the table, rubbing the balls of her hands into it for a second, then glanced at her stepfather. "I wasn't pranking her," she said at last.

"Okay, so you were just stalking her, then," John remarked.

"I wasn't doing that either!" Caitlin exclaimed. "I… I was in the area. It was a coincidence. I swear. I didn't know she was there until I saw her. I needed to tell her something, and I… I didn't know if I had the guts to do it face-to-face." She shrugged. "Turns out I didn't have the guts to do it over the phone, either. I wanted to. But I couldn't do it, so I hung up."

"Finally, we have something worth listening to," Sherlock said. "You needed to tell her something. What?"

Caitlin cast her eyes down. "I… look, I was just stirring shit, all right? I was going to tell her I was meeting someone."

"Oh, Caitlin," Merivale groaned, tilting her head back. She'd taken on the tones of an exasperated mother. "It's been a very long morning already, so please get to the point. Does this someone have a name?"

Caitlin looked at her stepfather again, but the older man's expression gave nothing away.

"Dyer," she said at last. "Detective Jake Dyer."