It was the mouth that most bothered me. Stretched wide in the shape of an orchid, it looked too large for her face. Lips, bold red against dark skin, glistened as though still flecked with spittle. I could almost see them quivering as a scream thundered past, soaked in abject terror. This mouth had gone beyond the tenderness of a kiss, beyond the civility of words, right into the realms of primal, animal fear.

The November breeze fluttered leaves across the victim like a blanket, crisp with autumnal auburn. They concealed her other mouth, opened involuntarily beneath her chin by a scalpel's acid bite. Her torso looked like a combine harvester had run over it; successions of ribbons and gaps where gentle curves should exist. The murder weapon itself had been left protruding from her genitals, apparently placed with care so as not to damage her.

A gloved hand intruded on my vision, retrieving the scalpel gingerly. My reverie broken, I followed it to an evidence bag.

"You won't find anything," I heard my mouth saying. "I'm not sure this one even has fingerprints."

The forensics guy snorted in agreement and shrugged. "We got to try, right?"

I pulled my coat tight, shivering. St James' Park, five in the morning, and I had another one. "How old were you?" I muttered, looking at the dead eyes to avoid seeing that mouth again. I didn't expect an answer, but Moore's voice intruded. My long-time partner, she still managed to sneak up on me every time.

"Sixteen," she said. "Maybe as young as fifteen. She's well used, Phil, and a user too - just like the others."

"Just another dead hooker," muttered one of the uniforms securing the scene, and I fought the urge to punch him. Instead, I let a tear track the shadow of my nose and spread salt between my lips.

Moore's hand patted my shoulder. "We'll get 'em, Booker. This is what we do."

I closed my eyes to the broken girl, and nodded.

*

The mist rolled in like an airborne tide as I strolled through the park. Needing my alone-time to mull over the case, I'd left the crime scene in the capable hands of my task force. London, a bustling cauldron of humanity most of the time, was cold and lonely during the grey darkness of very early morning. The air was almost impenetrable to the eye, but I knew where I was going. My footsteps echoed dully, their sound muffled by the mist, and I released a long breath into the ether. People could pass within feet under these conditions and never know.

After a few minutes, my legs brought me to the bench. It occupied a curve in the path between trees and had that embedded look of something that's existed for longer than one can reliably imagine. This bench was a resting place, a pause in time for journeys and travellers, and had played host to millions over countless years. The constancy soothed me, and I often sought refuge in its sage presence.

A tramp sat at one end, snoring gently, his dirty coat clutched tight for warmth. I rubbed my palms together, suddenly feeling the cold, and perched at the other end. Immediately, I felt at ease, comforted by familiarity. In the chaos of a fresh crime scene, it was all I could do to keep a handle on reality. The entire time would feel like a blur, a quick-fire succession of people, noise and questions. Here, reclined on my bench in the depths of London's oldest park, I could allow myself to ponder. I closed my eyes and took a gentle breath.

There were other advantages, too.

"This fiend evades me!" spat the voice next to me, and I smiled. "At every turn, he vexes my designs. Never have I encountered a foe so simultaneously vicious and devious."

"You'll get him, Clem," I answered, knowing he'd hear my words even though I only thought them. "It's what you do."

A snore emanated from the tramp, raising a tut from my ethereal companion. "Is there no debtor's prison for this wretched creature?"

I chuckled. "We don't lock people up for having no money any more."

"Well, therein resides your problem. Desperate men resort to desperate measures. Best to remove them from society."

"I know, Clem," I said with a smile, "the world's gone to the dogs and you wonder why you bother even trying to catch criminals. Come on, tell me about your case."

An audible breath emanated from the space next to me. "This one is desperate beyond imagining." Clement Booker, London detective extraordinaire, was my ancestor. By happenstance, he'd sat on this bench to mull over his cases, many generations ago. Via several psychiatrists and a close encounter with suicide, I'd eventually come to understand that I could talk to him when I sat here. To his credit, he'd taken my presence in his stride. I was a voice from the future, he the past, and we coincided here, on this ancient bench in St James' Park, to share experiences.

For every suspicion my mind raised, every nay-saying doubt, he'd provided an insight that helped me solve a mystery. I wasn't at all sure I was as helpful to him, but he seemed happy enough to converse.

"He holds a particular hatred for ladies of the night," continued Clem. "I do believe this hatred equals his fascination with the body and its mysterious workings. He cuts them, my child - cuts them wide open, with a surgeon's precision. On their posteriors, he exacts an emblem, cut in the shape of a diamond."

I snorted. "Talk to the prostitute community. One of them will be his mum."

"Are you sure? What makes you say this?"

"Trust me, Clem. I talk from long experience of psychologists. With these nut-jobs, it's always about their mother."

He sighed. "Do you jest, with your colourful language?"

I laughed, sending pulses of visible breath to merge with the mist. "Only a little. Call it irony - you'll understand in a hundred years or so. Seriously, though, speak to your ladies of the night."

"That is an unprecedented approach, but I have benefited from your futuristic ideas in the past, even if that does sound like a paradox. Thank you, my child."

"Quit that, will you? I feel like I'm at confession."

"I can think of no more appropriate form of address. You are after all, as much a child to me as it is possible to be."

"Alright, Grandad. I'll bear that in mind. Thanks for the chat - I need to get to work."

His laughter echoed in the mist. "Tell me if you require assistance."

Then there was just a snoring tramp, vibrating the bench with drunken rumbling. I put my hands on my knees and creaked upright. "I have a psycho of my own to catch."

*

"DS Booker, I presume," said the coroner, his voice heavy with sarcasm that didn't fit his words. "You're late."

I assumed an expression I hoped was 'professional perplexity'. "Sorry - inconsiderate murderer in St James' Park. Probably another of these." I indicated the body reclined between us. The exam room was cold, which felt appropriate, and excruciatingly bright, which didn't. The coroner was a middle-aged guy in a lab coat who looked like he wanted a cigarette, and I was in the way of him getting it.

"I got a heap more of these today. I can't just sit here and play with my arse while I wait for the Met to bother showing up."

I rolled my hand. "And I didn't come here for your cheery pep talk, so let's get on with it. What are your findings?"

He leaned on the side of the corpse's slab. "Well, she was murdered." I threw him a scowl that had no effect on his supercilious expression. "She's nineteen or twenty years old, and she's been a prostitute for at least three. Puncture marks indicate regular drug use. She has them between her toes, on her labia, and in her sphincter, so she's been using as long as she's been on the streets."

"So far, this fits the bill. What actually killed her?"

"Her throat was cut first, right through the jugular. Blood viscosity indicates she was almost dead when the rest was done," he met my gaze, all hint of sarcasm gone from his face, "but not quite. She's been cut from vagina to ribs, her womb extracted and stuffed into her mouth. There's a small incision in her heart, where the scalpel was left."

I swallowed. The sheer brutality still got to me, no matter the many murders I'd worked on. "Anything else?"

"One thing. Here, I took a picture - saves rolling the body. On her left buttock, there's a symbol carved. Must mean something, 'cause whoever it was took their time, and that's risky. Looks like a diamond or something."

"That's not a diamond," I said, feeling the knot forming in my gut. I pulled my mobile phone from a pocket and quick-dialled Moore. "Moore, I need access to Scotland Yard's archives. Can you get the paperwork started with the DSI? I need the old files - the REALLY old ones."

I hung up, and caught the coroner's impatient eye. "That's a symbol," I said. "A compass and a square, arranged to look that shape."

"Shit me a brick," he said, comprehension dawning across his face. "It's the god damned Free Masons!"

*

The archives smelled like a paper graveyard. Some vague attempt was underway to computerise the records and digitise everything in the vaults, but between security concerns and preservation worries, the job would take decades. The archivist walked us between rolling shelves, deep into the back of the building. Every footstep echoed, and our three sets of feet played out in canon as we walked.

"Are you sure the Masons had something to do with Jack the Ripper?" said Moore.

I shook my head. "Sure enough to come here and check, but no more than that."

The archivist snorted from in front of us. "There's more myth than fact surrounding these cases. You know the term Jack the Ripper was coined by a journalist after the fact? We'll find the information listed here under 'The Whitechapel Murderer'. Some believed at the time the Free Masons were involved, or that they hid the murderer, but that's probably because they're a secret society and nobody could find him. Most likely, he was just a sick nutter with a sharp knife and a lot of luck."

We turned a corner and found ourselves in a room that looked like it hadn't been used in years. A pristine desk with a single chair before it occupied the centre, surrounded by shelf after shelf of boxes.

"The home of Ripperology," said the archivist.

I chuckled. "Looks like nobody ever comes here."

"Ay - who wants facts when you can have so much more fun with fiction?" chimed in Moore.

Our host nodded as he headed back the way we'd come. "I'll leave you kids to it. Let me know if you need anything else."

We rifled through boxes for several hours without turning up anything helpful, but I couldn't shake the feeling something was there. I needed to know whether Clement Booker was chasing Jack the Ripper, and whether I had a copycat on my hands. If so, what were the odds we happened to be doing it simultaneously, and how could I use our bizarre connection to the mutual benefit of our cases? My mind was adding layers of weirdness to an already insane situation, but I couldn't shake the feeling everything was intertwined. The problem was, I couldn't share any of that with my partner without risking a visit from the men in white coats.

"So, if I'm understanding this right," said Moore, "there were two spates of murders. They occurred several years apart, had slightly different characteristics, and were never conclusively linked to one another."

I nodded. "It was the press that decided the same killer was responsible."

"What are we actually looking for? I'm not finding any connection to the Masons, but you seem to have something specific in mind. You're flicking through those papers like you expect a revelation, or at least confirmation of something you suspect."

"I'm looking for the symbol." I put down the stack I'd just finished searching. "I want to know if that Masonic design appeared on the ripper's victims. The cops at the time might not have made the connection - maybe it looked like a diamond or a square to them. I just can't shake the feeling it's here." I felt a throb pulsing at my temple and knew a migraine was imminent. I was getting too intent, again.

Moore peered at my face. "You need to calm down, Phil. You know what happens when you focus too hard. We'll catch this one - no killer this extravagant gets away with it. They leave too many clues."

"Jack got away with it."

"Yeah, well he didn't have us chasing him."

I smiled at her, taking in the dark curls of her hair with grey streaks mixed through, the earnest brown eyes. "Thanks, Jen. I appreciate it."

"Oh!" She held up a yellow slip of paper. "Is this what you meant?"

I walked round to her side of the desk. Sure enough, she held an artists' impression of a carved diamond, with rough detailing enough that I recognised the symbol, even if the cops in 1890 hadn't.

"Design found carved into 1888 victims," read Moore. "Then there's another note written below in different handwriting: 'Symbol not found on fresh victims. Does not support link to Whitechapel murders.' That's dated 1891."

"There's our link," I said. "We have a copycat, or a fan. Let's get this stuff boxed back up and get to the coroner's. We need to check the previous victims, see if this symbol is a common factor."

As we shoved files and folders onto shelves, a newspaper clipping floated to the floor. Picking it up, I saw a headline that turned my blood to acid in my veins.

Local Detective Victim of Leather Apron?

I knew what it would say before I started reading, but I couldn't tear my eyes away. Sure enough, Clement Booker, brave detective, had been found at the back of Castle Alley in Whitechapel, his throat cut from ear to ear.

My mind whirred as I tried to make connections, but one thought overrode everything else - I had to warn my ancestor. He was chasing the most vicious, cleverest serial killer in London's history, and if these files were to be believed, he'd end up dead, his quarry never caught.

*

"Clem, I need to compare details. I have a feeling our cases may be related."

Night held London in her clutch, the trees standing like eldritch sentinels in the gloom around the bench. The clouds had descended again, cloaking my favoured haunt with cold haze. No tramp shared the bench this time, but there were several close by, huddled in the shelter of trees.

"What leads you to this conclusion, my child?"

Picturing the piece of paper from the archive, I tried to make sense of my thoughts. "The diamond shape he carves into them - it's not a diamond. It's the symbol of the Fre-"

"Wait!" There was an undercurrent of fear in Clem's voice, though he tried to hide it with gruff forthrightness. "Do not tell me details, child. I should not know things that you glean from your history. We cannot tell what effect such untimely knowledge may have."

I huffed in frustration. "I help you all the time, suggesting approaches and things to look for."

"It is one thing to suggest which questions I might ask, quite another to furnish me with the answers."

"Clem, please let me help." I hoped my voice carried the weight of emotions I was experiencing. "You need to know this stuff."

He chuckled softly. "Your urgency tells me what you might say, my child. Consider me duly furnished with caution. I must live my life as I approach it, in a manner consistent with my intellect and time. What may change if I allow you to provide information I should not have? Perhaps we make a world where you no longer result, and this conversation becomes but echoes on the winds of destiny."

"Are all detectives wannabe poets in the 1880s?"

"You do entertain me, child. What an uncivil place your future must be, if all talk in the manner you do." He was still laughing under his breath, but even through my frustration I knew he wasn't mocking me. "What leads you to such revelations; surely you did not investigate a crime I am investigating, or is police time so cheap in the next millennium?"

I let the night hold me for a while, knowing my ancestor would wait patiently for my response. Helplessness was a common factor in my fears, every nightmare since youth involving a situation I couldn't escape. Right now, I was terrified. A cop's life is predicated on control; gathering the facts and sifting truths, ensuring that any conversation with a suspect goes where the interrogator wants. When you lose control of the case, you lose the perp. Philosophically, I agreed with Clem. If we were connected through time, and this wasn't some loony way I had of consulting my conscience, any changes I caused to his life could have major ramifications for me and my time. Trouble was, I had the means of control in my possession. I could give Clem the power he needed to solve one of the most famous cases in history.

My breath funnelled out like a dragon's smoke as I realised I didn't dare.

"We found something carved into one of our victims. It's a ... well; suffice to say it's in the shape of a diamond. Their throats are cut, and internal organs removed."

"What are you saying?"

"I'm saying we have a copycat. Someone in my time is replicating the murders from yours. You have to understand, Clem; your case is infamous, even though I can't tell you any details. In the here and now, everyone's heard of them. Academics spend their entire careers investigating the events you're living through."

His silence indicated thought, because I was sure I could still feel his presence. Eventually, his voice came through the night, quiet and composed.

"I believe you have told me too much, my child. However, that is no fault of yours. I may not be able to assist you, either. The copycat, as you call it, will be following in the footsteps of a legend while I chase somebody real. You must look to your lore."

"I'm sorry; I've cocked things up for you, haven't I?"

"Not at all, my colourful progeny. Still, I must away. Until next time."

The presence faded into the mist, and I was left to shiver in my guilt, alone on a cold London night.

*

"I've compiled all the coroner's reports," said Moore, fiddling with her laptop computer. The projector sputtered a pale image onto the wall as I perched on the side of her office desk so we could review the case. She'd bought us both coffees in those cardboard cups that keep if hot for hours. You needed props to work on a case. With no smoking allowed inside any more, coffee was the new drug of choice.

Ghostly images of dead faces spread across the wall, their eyes closed and their necks wide open. "Four victims," I said, stating what we already knew. Sometimes, spelling out the evidence aloud was all it took to break a case, to find that vital link that pointed to a killer. "Each had her throat cut by a right handed assailant, from in front rather than behind. All were working prostitutes, and all drug users to one degree or another. They were found in various locations around South London, with no apparent pattern or clustering."

"Each one was mutilated," said Moore, taking up the narrative. "Mutilations occur immediately after the mortal neck wound, meaning they're still alive when the killer cuts into them." We shared a look. "The cuts are made with near-surgical precision, by something extremely sharp - most likely, the scalpel that's left with each victim, never with trace evidence on it beyond the victim's blood. All the mutilations have something sexual about them, whether it be uterus removal or repositioning, the scalpel in the vagina, or the first victim, whose hands were arranged so they grasped her reproductive area. No evidence of semen or sexual assault in any of the victims."

I sighed and sipped tentatively at my coffee. "To do that kind of thing - calm and calculated, no frenzied stabbing - takes full-on detachment. I doubt the killer knows the victims. If it's a guy, he doesn't do it for a turn-on, so it must have to do with the body itself; reproduction or the process of birth." I snorted suddenly, remembering what I'd said to Clem. "It's always about the mother."

Moore chuckled. "Damn right, but even if you're onto something, I'm not sure how we can use it."

"It's something to bear in mind, that's all. Do we have the full report on the latest victim yet - the one from St James' Park?"

"Ay. The call came in from the coroner earlier but I couldn't get hold of you, so I went myself. Charming bloke, isn't he?"

"I think that job breeds sarcasm," I said with a chuckle. "Did he come up with anything unusual?"

She nodded. "You could say that. He checked back, and the first two victims had that symbol on them, just like the third."

"I sense a 'but' coming."

"Our St James' Park victim doesn't have it. Same cause of death, and similar mutilations, but no Masonic symbol."

I stood up, the need to pace filling me as thoughts flooded my head. "He's broken the pattern, changed his signature - why?"

Moore was watching me pace, a small smile twisting at her lips. She took a long slug from her drink before replying. "It's a different killer."

"No," I shook my head, "it felt the same, and not enough details hit the media to account for all the similarities."

"The killer was interrupted." She was grinning now - she always did when a case took me like this. Still, there was no room in my head to be patronised right now.

"Not likely. The mutilations were still there, and care was taken with the scalpel placement, which meant the ritual was finished."

"Well, this could all be part of the scheme. Remember what we found in the archives - the later set of victims from 1891 didn't have the sign carved into them. Perhaps this is a reference to those."

I paused for a moment, but quickly realised I wasn't convinced. "If that were the case, we're short a murder - there should be four in the first collection, not three, and there's been no appreciable gap in the timeline. If you're copycatting, those details are important. No ... I think this is a break in the pattern."

"Okay, genius," said Moore. "In that case, the acid question is 'why'. You only change a pattern that's been working for one reason."

I looked her in the eye. "To hide it."

"Exactly. And you only hide something if it's incriminating."

"We've come close," I said with a laugh. "Something we've done or publicised has the killer scared, so they've changed to throw us off the scent."

"Ay," she replied, draining her coffee. "But which scent?"

*

My feet kicked the ground-hugging mist into eddying dances as I strode through the pre-dawn grey of my favourite park. Something nagged at my mind like a stone in my shoe - a creeping revelation that refused to break cover but scratched insistently at my awareness. I'd been up all night with Moore as we thrashed out scenarios, pooling our experiences from past cases as we sought that one vital link; the action we'd taken that pushed the killer to alter their routine.

Our ideas exhausted with no satisfactory explanation reached, she retired to bed and I headed for the bench. If Moore couldn't help, perhaps Clem could. It struck me I didn't even know how far along Clem's investigation was, how many murdered prostitutes he'd added to the tally. The newspaper clipping about his death came from the bottom half of a page, eliminating the date. My brain started to wonder whether I'd still be able to contact Clem if he died, whether time moved for him as it did for me, and what would happen afterwards, but that was a mystery best left for another day and a long session in the pub.

A tramp was once again propped up at one end of the bench, the vibrations of his slumber floating on the air. As I approached, the sheer beauty of the scene struck me. The bare trees shivered with the cold, silhouette limbs clasping at the sky. An old-school London lamp post lurked amongst them, throwing an ethereal cone of light through the mist, illuminating the bench across the path with a moon-like glow. The bench itself was cast iron with solid oak slats, as enduring as the trees and foundry that created it. Such places existed across London, small nooks and pockets standing out of time, a testament to the enduring culture of an ageless city.

I took my seat, listening to the welcoming creaks as the bench and I settled into one another, and wondered what the hell Clem might say that could help me.

"We cannot speak long," said his voice almost immediately, startling me. "I am on my way to Castle Alley - my attention is required there. I wanted to stop here first, my child. There is a grim chill on the air, and I am urged to speak to you first."

Fear seized my heart like a vice. "Clem, that alley-"

"Speak not!" His voice forced me quiet, rife with authority. "Some things are not for us to reveal. Please, avoid telling me anything. I am here to tell you something, though it may be of little use."

Trying and failing to hold back helpless tears, I sniffed to clear my voice. "I can help you, Clem. It doesn't need to be this way."

"Need does not feature, my child. The way simply is. Now, would you know my trifling thought or not?"

I smiled. "It's been my experience that, when investigating murder, there's no such thing as a trifling thought. Everything has its place, and sometimes that place helps you catch a really sick fuck. Your trifle could save lives."

"You are wise, child, despite the vibrancy of your tongue." I felt a sense of approval sweep over me as he spoke. "I was pondering what you said about your 'copycat', and something struck me." He paused briefly, as if to be sure of himself. "The diamond mark has never been revealed to the newspapers. Given the obscurity of the clue, we have not felt the need to divulge its existence. It is rarely spoken about, even amongst the detectives. I believe it exists only once in the general records of the case."

"That's what I wanted to tell you about, Clem - the last victim doesn't have the mark. The pattern has changed, and we can't figure out why."

"You miss the point. If knowledge of the diamond is so rare in my time, then-"

And there it was - my stone uncovered. I felt my body jerk as realisation rattled through it. "Then how did the killer know about it in my time? Holy crap, it could be a cop! No, that doesn't fit - the archive hadn't been touched in years. There's no way they could know a detail like that."

"There's one way," said Clem, his voice loaded with meaning. Suddenly I was very aware of my connection to the bench beneath me, the strange circumstance that allowed me to converse with my ancestor.

"Bugger me, it's this bench - there's someone else using it, another ancestor with another link. The killer is talking to your Whitechapel murderer, comparing notes! That's why the last victim didn't have the diamond. Clem, it was too close to here - just a few minutes' walk. The killer changed the pattern so we'd think it was someone else, so I wouldn't make the connection to this place." I grasped my hair in frustration. "It was in front of me the whole time."

"Child!" hissed Clem's voice. "If that is the case, then your killer knows about you, about us."

I started to deny the possibility, but felt the oak slats shift beneath me.

"What?" I said, turning my head. The tramp reared up in my vision, a short black club flying towards me, and I had no chance. Something hard but wrapped in softness exploded against my skull and the world turned a hazy shade of white.

"You never thought to check, did you?" said a voice, muzzy and thick to my ears. "We are the ones you don't see, Detective. Those you don't try to identify; just a bad smell on the edge of your awareness. But we have POWER, Detective, when we choose to take it. The greatest power in the world - anonymity."

I blinked but it made no difference. Somewhere in my consciousness, I could hear Clem's voice calling my name. "Clem," I mumbled, not sure if I was even coherent. "Don't go to Castle Alley."

Then another impact thundered against my mind, and white turned to black.

*

"They came too close, my Lord - we must change the plan!" Charles Bant, Lead Disciple, shrugged his smelly tramp's garb into a more comfortable position on his shoulders. He clubbed Phil Booker's limp form again, as he was bade. Six months ago, he'd never have dared do such a thing, but Charles Bant suffered a spiritual awakening.

"Fear not, my child," said God. "You will deal with your detective, and I have imminent plans for the one he speaks to. With them removed, we will be free. Our work must continue. My body may be dead in your time, but my soul will be ravenous for the gifts you garner."

Charles shoved the Billy club into his jacket and set about stripping Booker of his clothes. "What should I do with this one, Lord?"

"I have no use for males, but I cannot risk the competition in the afterlife. Strip him of his manhood and carry it far from his body."

"Of course." Swallowing the vomit that rose in his throat, Charles took a new scalpel in his gloved hands and set to work. "What should I do next, my Lord? What would please you the most?"

A soft chuckle echoed through the mists of dawn. "Prepare me more concubines, my child. I am hungry."