Dennie Finn was corpulent and the wrong side of fifty, wearing an untucked blue denim shirt and trousers that had probably fit him ten pounds ago. But, Lestrade reflected, in all fairness, he probably didn't look much like Mr. GQ either when he rolled out of bed at four in the morning to attend an incident. If the London Zoo's reptile care services said that this guy was an expert in his field, that was good enough for him.

"Oh, yes," Dennie said jubilantly, voice muffled by the car door as he stooped to peep under the car. From where he was standing, Greg couldn't see the snake, but he heard a low, threatening hiss. "Oh, look at you, girl. You're beautiful, aren't you?"

"Beautiful?" Greg huffed.

"Gorgeous. Look at her colour. Egyptian Cobra, looks like - banded cobra. She's not real happy though, is she? Hang on a tick, I'll get her sorted out and then we'll jabber about it."

Greg thought for a second whether it would be necessary to explain that the beautiful banded cobra wasn't happy because he had reflexively kicked her, then decided to leave that detail out. After all, the guy had said she was unhappy, not dying.

Dennie pulled a long-handled implement out of the back of his own car. It had a metal hook on one end that reminded Greg, for a moment, of the shepherd's crook used to yank bad performers offstage in old Bugs Bunny cartoons. He forced himself not to flinch as Dennie used the business end of the crook to yank the snake toward himself. She uncoiled like lightning and hissed again, but before she could go on the attack he'd used the stick to lift her into a waiting sack.

"There we go," he said, knotting the thick hessian sack and apparently unconcerned about the furious movement from within it. "She'll be okay."

"Oh, good, I'm so relieved," Greg muttered.

"Reptiles are diurnal - they have to be, 'cause they've got cold blood, you know? It means they get a bit pissed off if you suddenly shine a light on them. And if you stick them somewhere dark, like the inside of a sack, they think it's night-time and curl up and go to sleep. I love them, but I'm not going to tell you they're bright."

"An escaped pet?"

Dennie shrugged. "Maybe," he said. "I mean, I've never come across anyone with a snake this exotic, but, you know, there are people who are collectors."

"It's legal?" Lestrade had no interest in, and therefore little knowledge of, laws surrounding keeping exotic animals as pets.

"Sure, it can be, if you apply to the right people and get the right paperwork. When you and I were kids, there were rich people wandering around Notting Hill with leopards on leashes and baboons to answer the front door for them."

A sudden memory loomed up in Greg Lestrade's mind. He'd been a very young child - maybe five or six - in the days when Carnaby Street had still been swinging. His Aunt Kathy had taken him to London for a treat, and it had been a day of wonder for an easygoing boy whose idea of a perfect life was ice cream every day and Doctor Who on telly. When he'd expressed understandable skepticism about whether a person could really buy anything from Harrods, she'd insisted: no, Greggy, it's true. You could buy a gorilla from Harrods if you wanted, or even a lion. Imagine that! Going to the shops to buy a lion!

It had become a staple schoolboy fantasy for a year or two after that: one day, when he was all grown up, he was going straight to Harrods to buy a lion. Even though he hadn't the faintest clue what he would do with it after he bought it.

"So where are you taking it now?" he asked Dennie. "Sorry, but since it was chucked in my car, and..." He stopped before he could mention the note. Even though it wasn't Shakespeare, it was still something he didn't want the media to get their teeth into. "It was thrown into my car," he said again, pointing to the broken window. "Which is a crime, last time I checked, and if this thing's been stolen or smuggled, that's a crime, too. I'll send officers over to pick it up. What address?"

Dennie told him, though he seemed disappointed that his new acquisition was to be taken from him so soon. "They'll look after her, right?" he said wistfully. "I mean, I don't reckon there's a fully-stocked terrarium in every police station, you know?"

"You can figure that out with the officers when they come round. It might be able to stay with you. I don't know. It's not staying here, anyway."

#

Melissa Brennan was having a very bad ten minutes.

She'd arrived on the scene of the Jones murder only a little behind Merivale, who reflected that Brennan must be able to drive like a demon to be able to keep up with her when she didn't even know the area. It hadn't taken long to convince the detectives at the door to let her in, even though she didn't look like a forensic psychologist and they'd never seen her before.

The smell hadn't given anything away. Bleach. Nothing offensive. She'd unsuspectingly greeted Merivale and joined her and Sherlock in the bathroom - and then, looking down at the dead woman still lying in situ in the tub, had suddenly become unwell. Unwell enough that she was now sitting on the toilet lid, her forehead on her knees, taking deep breaths. Sherlock was, of course, standing next to the bath looking at her as if she were growing some interesting new species of bacteria, but June Merivale had got down beside her and put one hand on her shoulder.

"Come on, love," she said, and Sherlock once again thought of the toddler and his mother in Smithfield. "Chin up. She's not in pain or anything." She paused. "You've never seen a dead body before?"

"Not like that," Melissa admitted, though neither Merivale nor Sherlock would have classified the body in the bath as graphic.

"Haven't finished your probation, have you?"

Melissa shook her head, and Sherlock refrained from telling Merivale that Melissa had still been working on her PhD when Greg had met her, and she had only just started her probationary work.

"Sherlock," Melissa said, "if... I mean, if you... Greg..."

"I am the soul of discretion," Sherlock said, without any hint of sarcasm or mischief.

Melissa opened her mouth to say something else, but before she could, they all heard an almighty crash from the front of the house and at least two voices - male, raised in urgency, if no real anger. And then a jagged, drawn-out scream. The sound of a man inviting all the demons in hell to descend upon him and put him out of his misery.

Sherlock looked at Merivale.

"Colin McGowan," she said quietly. "Jones's partner. He's been living here with her for four years."

"How do you know?"

"He's her next of kin on her employee file. I used it to get her phone number earlier. Teaches English Literature at the University of London. I think he could teach us a thing or two about Shakespeare. We need to interview him. As soon as he calms down - it can't wait."

Melissa looked at her. "Oh," she said, as the penny dropped. "You can take your time cleaning up after a murder if it's your own house and you know nobody's going to interrupt you."

"Exactly. Sherlock..." Merivale, helping Melissa to her feet, turned to him. "God help me, I'm going to regret this," she said, "especially since you're still technically in custody. But I'd like you to sit in with us, please."

From the front step, they heard another howl of anguish. Sherlock raised one eyebrow. "Why?"

"Because you're a man."

Sherlock looked more confused than ever.

"I just want you to catch his arm if he takes a swing at me," she said.

"Oh," he said. "Yes. I - I suppose I could do that, yes."

It was ten or fifteen minutes before Colin McGowan was coherent enough to be interviewed. There really wasn't enough room in the kitchen and the entire house was now an active crime scene being combed over by the forensics team, so Merivale led the way out to one of the cars and opened it, letting McGowan get in and sit down. Melissa, almost on auto-pilot, climbed in to sit on the other side of him but Sherlock, mindful of his role to grab McGowan's hand if he tried to swing at Merivale, remained standing with one hand resting on the door. He had no idea how he was supposed to prevent it if McGowan decided to punch Melissa.

But it seemed as if McGowan's anger had sparked up, exploded, and burned out on its own fuel. The fortyish academic had a sleepy demeanour that reminded Sherlock, before he could help it, of an old illustration of the dormouse from Alice's Adventures Underground. There was nothing remarkable about McGowan. Thinning hair, decidedly paunchy. An odd match for Lauren Jones, who was nearly six foot tall, blonde, bronze-limbed and outdoorsy.

At least, she had been.

Someone had given McGowan a tissue, and he was wringing it into a tight cigar shape in his hands, as if testing how far the tissue paper could be pulled before it gave out.

"Colin," Sherlock said before anyone else had a chance to. He held one hand out to McGowan, who looked at it in hesitation for a few seconds before giving it a quick pump. "Is it OK if I call you Colin? I'm Sherlock Holmes. Hi."

Melissa shot Merivale a glance before she could stop herself. Sherlock had not only completely changed his accent, he'd also changed his body language and the timbre of his voice. The world had apparently lost a fine actor the day Sherlock Holmes decided to be a detective.

"Not really in the mood for a chat right now, sorry," McGowan rasped.

"I know. We're sorry we have to ask questions so quick." Merivale's tones implied a but that never came. "Where've you been, Colin?" she asked him instead.

"The pub, obviously," Sherlock interrupted before McGowan could speak. "It's nearly an hour past closing time, and he reeks of beer. Where he was isn't important right now. Mr. McGowan, what can you tell me about Hamlet?"

"Hamlet?" McGowan repeated. "You mean, the play?"

"You've got a lot of friends down at the pub named Hamlet, have you?"

McGowan glared at him for a few seconds. "I've just got home and found the woman I wanted to marry got murdered," he said. "So I'd really appreciate you not being an arsehole, yeah."

Sherlock threw his hands up in good-natured acquiesce, but he glanced at Merivale again and hoped she'd noted it on her own: Colin McGowan's grammar wasn't instinctive, and his vowel sounds became distinctly Glaswegian when he was upset.

If Merivale had noted it, nothing in her expression betrayed it. "Did Lauren say anything to you in the last few days about a case we've got active?" she asked gently. McGowan wiped his nose on his sleeve again.

"Well, I knew you had one," he said. "I thought it might have something to do with that copper that got murdered a couple of days back, but she didn't tell me anything about it. Never does. I don't normally ask."

"Did she seem unusually apprehensive about something to do with this one? Preoccupied? Maybe even afraid of someone?"

McGowan shook his head.

"Had any odd visitors recently?"

He thought about this one. "No," he said. "I mean, we're not recluses. We've got lives..." He trailed off, as if the reality of it had only just hit him: Lauren didn't have a life anymore. "But, uh, the only visitors we've had over to the flat in a week have been her brother and mine. That's not odd. They come over all the time-"

"That's not important either," Sherlock huffed. "But this is: Colin, let's go back to Hamlet. Tell me about Ophelia. How did she die?"

McGowan looked at Sherlock as if he were insane. "What the fuck does that have to do with-"

"Just answer, please. You've taught it at the university, surely."

The tissue in McGowan's hands suddenly snapped, and he dropped it into his lap. "Hard to say," he finally said. "Most productions go with her drowning herself, but Gertrude doesn't say for sure she did it on purpose. Ophelia was deranged by that point. She was picking flowers by the river... might've leaned too far out, fell in, was too mad to get herself out again. Suicide was a sin in Shakespeare's day, meant you were going straight to hell, so he probably didn't want to lay it down like that as a fact. But what-"

"Okay, I've heard enough." Sherlock rose, but before he could say anything further, his phone rang. Excusing himself, he plucked it out of his pocket and wandered back toward the house to answer it.

"You got anywhere you can stay tonight, Colin?" Merivale asked him.

McGowan wrung at each finger in turn. "Uh, yeah," he muttered, giving another sniff. "I s'pose I could stay at my brother's house..."

"Okay," she said, getting up. "Come with me, and I'm going to introduce you to one of my detectives, Sarah Draper. Sarah's going to be your Family Liaison officer. She'll be available to answer any questions you might have about what's happening with the case, as well as arrange for family to be contacted, accommodation if you need it, things like that..." She stopped short. Both she and Melissa had just heard Sherlock say, "Are you all right?"

They looked at each other, and Melissa got out of her side of the car and into Sherlock's line of sight, gesturing to him with one hand. But he was clearly far away in thought. "No," he said into the phone. "Neither of you...? Hayley...?"

There was a long pause. Sherlock took a deep breath.

"We're coming back now," he said. "Wait for me."

Without bothering to say goodbye, he hung up the phone and put it back in his pocket. It was only then that he turned to Melissa, as if he'd only just noticed she was there. "That was Greg," he said. "There's been an incident there, just after we left."

"An incident?"

Sherlock remembered Melissa's reaction to the news that Greg had been in a fire at Borley, even though Greg had made that call himself and assured her that he was perfectly safe. "He's all right," he said. "But we need to leave. I'm driving." He pulled Melissa's keys out of her jeans pocket, scrunching them almost violently into the palm of his hand.

"You've got my permission to go," Merivale said, rolling her eyes.

"Yes, fine." Sherlock was no longer listening. "Don't waste time chasing leads here, Merivale. I'll call when I can."

He turned to head toward Melissa's car, but Merivale darted forward and clutched at the sleeve of his coat. He stopped, drawing his hand back as if she'd bitten at him.

"I can see why Greg works with you now," she said.

He looked at her.

"Stay safe." She let go of his hand and went back to the car where McGowan was waiting for her.

When Sherlock and Melissa returned to the house, they found Greg and Jake with Hayley in the kitchen. No sign of any snake. In the meantime, John had come home from dropping Molly off at Barts. They met him on the doorstep and came in together. Charlie was asleep against his shoulder, and he seemed reluctant to put her down anywhere, as if he didn't quite believe the snake had been apprehended.

"Not McGowan," Sherlock announced as he entered the kitchen.

"Who's-"

"Keep up, John - Jones's partner. Shook my hand. There were no defensive wounds. And when I asked him about Hamlet, he had no idea what I was talking about - the Shakespeare link hasn't been leaked to the press. His answer when I asked whether he thought Ophelia drowned herself or whether it was an accident was particularly enlightening. Like a good academic, he considered the text and the context, and didn't bring any of his own assumptions into it. He had no idea I was referring to his partner. Lestrade, the note left in your car's just changed the case more than the snake. Have you heard of William Hierens?"

Lestrade, in mental whiplash from the breakneck speed at which Sherlock had moved from Ophelia to William Hierens, thought back for a few seconds.

"No, it's an historical case, Lestrade. Before you were born."

"Oh," he finally said. "He wasn't that kid in America, with the lipstick?"

Sherlock nodded. "In December of 1945, Hierens, who was seventeen, stabbed a divorcee named Frances Brown in her apartment in Chicago. He wrote on the wall in her lipstick: For heavens sake catch me before I kill more I cannot control myself. The parallels here are obvious."

Lestrade raised one eyebrow. "You think the killer sent that message, saying 'I've done something I really shouldn't have, here, straighten it out before she dies'?"

Sherlock bit his lip, deep in thought. "I don't know," he finally said unhappily. "I don't understand the connection between the note and Jones's murder. Why write "help her" after attacking Jones? Besides, by the time that note was left, Jones had been dead for at least two hours. She was well beyond help, and the killer would have known that."

"A taunt?"

If Sherlock's ego had permitted it, he would have shrugged.

"Who was the snake intended for?" Lestrade continued.

"You," Sherlock said. "It was dumped in your car - when both Melissa's and Dyer's were parked nearby. Obvious."

"I look like Cleopatra, do I?"

"I think we've established that the killer isn't interested in exact mock-ups of Shakespeare. He didn't even bother leaving a note with Lauren Jones."

"Yeah, that was rude of him," Greg muttered.

"Celeste's murder was neatly done. The killer was prepared enough to bring their own paper and nail to the scene. But remember - it was Thompson who was killed first, and the wine came from wine boxes in his own refrigerator."

"Maybe the killer had visited the house before, and knew they were going to be there," John suggested.

"It's possible. But Thompson was drowned in water. Almost as if it were a blitz attack with no preparation, and the idea of staging it to look like something out of a Shakespearean play only occurred to them after. If you check with forensics, I think they'll confirm that the note left with Thompson was written on his own notepaper, with his own pen, after he was dead. But the one on Celeste would have to have been brought to the crime scene. All prepared."

"So what's that mean?"

"It means that the use of Shakespeare has nothing to do with the case, except to prove we're looking for someone able to Google Sparks Notes on Shakespeare."

"Which is pretty much everybody," John muttered, thinking back to Molly's remark when she'd Googled the Macbeth reference: you might have thought of it yourself, if you weren't so old-fashioned. Old-fashioned? Can't a man even read an actual newspaper these days without getting stick for it from his wife?

"There's one thing I don't understand," Sherlock continued.

"Oh, my God," John said. "Someone alert the press, quick."

"Oh, shut up. What I'm trying to say is, Celeste and Thompson were killed in a decisive, purposeful way. Nothing was left to chance. This killer is changing their MO with every murder, but why would they regress from stabbing someone to death to putting a snake in their car and leaving it entirely to chance, firstly that they'd be bitten, and secondly, that they wouldn't be able to access medical help before they died? As a murder technique, it's alarmingly ineffective." Sherlock took a breath. "Either way, the only solution I can see for this problem is this: We let the press run a story about your tragic death by snakebite, and then we wait for the killer to get confident and make a mistake."

"Sorry," Greg said. "What?"

"You heard me. From now on, the only people who know you're not dead are in this room." He paused. "And, I suppose, we should include Molly in that. I trust she can keep a secret."

John coughed.

"Wait," Greg said. "Wait... you mean you're going to tell my mother I'm dead? My mother, Sherlock. I hate to say it, but even after all this time, I'm still kind of fond of the old bat. I don't want her to keel over and actually die over this."

Sherlock shook his head. "There's no point in putting out a press release if you're going to tell a dozen people it's not true. People talk. They can't help themselves. The only reason I'm suggesting we tell Molly you're not dead is because John couldn't tell her a convincing lie if his life depended on it."

Lestrade felt the implication like a kick to the chest: if Matthew was somewhere he had access to newspapers and telly, he'd be one of the first to hear that his father had died. He shook his head. "No. Might be all right for sociopaths, but I can't let my family think I'm dead."

"It can cause complications, I'll grant you." Sherlock spoke without smiling. "But actually doing it is surprisingly simple. Despite my reputation, I don't condone staging a suicide for fun. This is life or death. The only way we can keep you safe for now is to pretend their murder attempt succeeded. They won't try to kill a dead man."

"Greg," Melissa spoke up. "He's right, you know. Whether the killer is trying to get at your family, your team, or both, you're the ultimate target. If they think they've succeeded, it's possible the only person who will die next is the killer."

"Why the killer?"

"People who go on murder sprees of this level and speed usually end them by committing suicide." Melissa sounded matter-of-fact. "Even if they don't go to that extreme, they're likely to move out in the open over something like this. It might be the best chance we have of catching them."

Lestrade thought this one over in silence.

"If you think it'll help, do what you need to do," he said.