It was almost too easy to get them here. We watched them get in from the bar, DiMarco so drunk she could hardly make the steps to the building. Greco laughing at her stumbling, making no attempt to help her out as she crashed against the brightly painted plaster that was peeling with age and neglect.

First Lumen, crouched in the darkness of the bathroom, injects Tina with the M99. It's her choice to wait for the woman in the salmon pink tiled room; she knows it would be the first place she would go when she got home. She gently folds the sagging body to the floor and waits for me.

Greco's slumped in the armchair, manoeuvring the remote control within reach with his foot. It's child's play to sneak up behind him and plunge the needle into his neck. I lift him into my arms and carry him out back, into the darkness from which he will never return. Once he's on the table, stripped and secured in clear wrap, I go back for Tina.

Lumen gets to work without speaking, the plastic wrap taut in her hands and her face in grim concentration. She undresses DiMarco efficiently, like a nurse. Without a pause she passes the roll under the table and back. Again and again she cocoons the skinny woman in her transparent shroud. When she looks up at me her eyes are alight with a sort of ferocious energy. She grins, her teeth sharp and white in the glare of the bright over head lights.

"What do we do now?" Her voice is laced with menace. The combination of the approaching kill and her presence is a heady cocktail. My blood is racing again, heart hammering to keep up with the demands of adrenaline and arousal.

"Make sure we're ready for them." I drag my eyes from her curves, the black material of her kill outfit making her seem supernaturally present in the glimmer of the plastic, and focus on checking that the cord for the chainsaw is not hampered by the position of the table.

"You know it isn't Dexter, you've done this hundreds of times. Why are you checking now?" Harry follows my gaze to where Lumen is standing, looking down at Greco with her head cocked on one side like a lioness regarding a fallen gazelle. He nods at me, biting his lip. Even Harry can see how she affects me.

I am acutely aware of her as we move about the room, tucking in plastic, smoothing out sheeting. It's as though my senses have been rubbed raw, every one of them screams her name. Without looking I can feel how her breathing disturbs the air around me, the heat of the room making it hard to think of anything but her.

There's no reason to wait. We both know that we are prepared, focussed and sharp. She passes me the capsule that will wake Greco, I snap it under his nose and he starts awake with a grunt, the chemicals clearing his brain of the fog of drink and the sedative.

"Where...?" He doesn't finish the word before he arches up, straining at the plastic. His bindings hold him firm, squeaking as his sweaty skin wriggles in its embrace.

"Hello." Lumen's voice is quiet, controlled, it makes my blood boil. His eyes flick to hers, wide, so wide I can see the whites of his sickly eyes.

"You... what the fuck?" She holds out her hand for the gauze, I pass it to her and she stuffs his mouth. He gags and her lips pull back over her teeth in a frightening smile. She flicks her gaze to me and I swallow. She is so dangerously beautiful.

"Shhhh." Her face is close to his, so close she could kiss him. I watch her lick her lips. Unconsciously I run my tongue over my own and imagine pressing them against her mouth; they will be hot and wet. I lean back, hands propping me against the metal countertop. "We're going to kill your girlfriend." Lumen grins viciously as Greco bucks in the binding plastic. She looks up at me and her smile becomes amused at his antics, as though we are watching one of those shows where stupid people do stupid things on video camera. I smile back, she arches an eyebrow and the look is like ice through me.

"Oh don't worry, you won't have too long to deal with the horrible images." I bend over his body, muffled cries coming from the gauze and his breath heaving his ribs up against the sheeting. "Because we're going to kill you right after her." He goes still and Lumen laughs. She trails a finger down his body, a frightening parody of eroticism, the gesture teasing, like foreplay. Greco goes bone still; his eyes are still wide and scared. Lumen whirls around, positioning her body so he can see the prone form of his girlfriend. He moans.

I am at Tina DiMarco's side, the vial of ammonia in my hand. One snap and she is wide awake, her eyelids flicker and then snap open. She takes in her surroundings in an instant.

"Jason?" Her voice is mumbled but she sounds surprised. I screw up my face and shake my head.

"Nope, sorry Miss," I drawl, in Jason's loser twang. Tina's eyes narrow warily. She hears the muffled noise of Greco on the bench and her eyes swivel to him, widening in alarm as she sees where he is and what we have done.

"What? What are you doing?" Her voice rises two octaves.

"We're avenging your son. We can't undo what you did but we can make sure you never do it again." Lumen points to the sad pictures of Todd DiMarco above Tina's head. Tina makes a gulping sob.

"Oh god, oh god. I never meant to... I was scared... of him..." She flicks her eyes to Greco and he makes a strangled noise. I realise he is laughing. He tries to speak. Lumen reaches over and removes the gauze from his lips.

"Scared, honey? Of me? No, no, you begged me to get rid of the little bastard..." Lumen's heard enough. She reaches for the chainsaw, switching it on briefly and revving it with a terrifying noise and then passing it to me. A trickle of yellow fluid drips from under Tina DiMarco's plastic sheeting. This evidence of her fear rolls away, as though it's trying to escape this situation.

"You can't do this! You're a monster!" DiMarco begins to shout and Greco opens his mouth to join her, clearly thinking to attract outside attention but Lumen stuffs the gauze brutally back into his mouth. I bend to Tina DiMarco, her eyes rolling wildly in her head. Her limbs flap against her confines.

"You murdered your son, as clearly as if you'd beaten him to death yourself." My voice is calm, the ecstasy of peace falls over me as I relish the moments before the chainsaw comes down.

"You were his mother; you were supposed to protect him. You don't deserve to live." Lumen hisses this through her teeth, her voice is passionate and yet cold. It thrills through me. The scalpel is in her hand and it flashes across Tina DiMarco's cheek, leaving a slim trail of blood in its wake. I take the pipette and drop the blood onto the slide. I squeeze it shut, the drop blossoms out.

I rev the chainsaw and Tina DiMarco starts to cry. Lumen gags her mouth and I bring the jagged teeth of the power tool down and watch as it slices effortlessly through her captured limbs. The sound of crunching bone, severing flesh and the fantastic crimson spray of blood is like a new baptism. I glance to Lumen, her mask is over her face and through the red, red spatter of Tina DiMarco's life I see her fierce grin.

It doesn't take me long to finish with Tina, murder becomes disposal as her body is destroyed by the chainsaw. There is a thudding noise behind me and I turn in my work to see Lumen staring down at Greco, his feet banging in vain against the bench. He is making strange whining noises.

"Is this how Todd sounded when you beat him to death?" Her voice is a razor blade in his ear. He flinches from her. "You're the monster here. We're just cleaning up the mess." He closes his eyes and her fingers flash out, prising his eyelids open, pressing painfully into his skin.

"Oh no, you get to watch. You don't deserve any fucking mercy." I step back like a magician to reveal the neat but bloody packages which are what's left of Tina DiMarco.

"Your turn now, I tell him, flicking my eyes to Lumen who is standing there, blood flecking her skin and the plastic apron which moulds to her breasts and belly. She makes my heart beat faster, this tension is almost painful.

Greco twists painfully like a caterpillar that can't quite turn into a butterfly. His cocoon holds him still for his final transformation. He moans and his eyes roll back in his head as the image of the piles of flesh that were his girlfriend becomes too much for him. Lumen laughs, the sound like crystal shattering in the muffled atmosphere of the kill room. She smiles at me and crosses to where I stand, chainsaw silent now, dangling from my hand. She lifts her visor and her face is startlingly clean, only a line of blood which has escaped the protective plastic curves along her jawbone.

Her hands reach up and she moves the blood spattered screen from my face too. Her fingers curl in the back of my hair and she pulls me down to kiss me. Her lips are searing hot and she opens her mouth and sucks at my tongue. A bolt of desire goes through me. I drop the chainsaw, not hard but it clatters with a sound that seems indecent. I push her back against the bench where Greco lies moaning, still twitching in his plastic wrap. She grinds her hips against my crotch, I growl into her mouth and she pulls back her head and sighs.

My gloved hands are on the plastic covering of her breasts and even through the protective layer I feel her nipples, hard and wanting. Her arousal finds its echo in my body and her fingers trail down my side and slide between us. She moans when she closes her fingers around my hard cock. I put back my head and pant her name. She presses her mouth to my neck and licks and sucks a line down to my collar bone. I don't know if there's blood there and the grotesque thrill of not knowing sends a shiver through me.

She is stroking, teasing, squeezing and I'm not going to be able to hold out much longer. All I can think is how hot she will be when I am inside her, how tight and that terrible, wonderful feeling of possession, of being owned body and soul.

Greco makes a muffled scream and Lumen stops, resting her head against mine like she did before, panting and smiling to herself. I open my eyes and look right into to that dark stare. She is grinning now.

"Oh, we forgot someone." She pushes back against my shoulders, bucking her hips against me one last time as she propels us away from the table. I pick up the chainsaw and hand it to her like she's in a ceremony. She bows her head in thanks.

"Srry Joe, got a little carried away there," I say jovially, smiling down at him as I flip the visor down and see out of the corner of my eye, Lumen wiping her face with a paper towel. Somewhere inside me registers that she licked the blood from my neck and the thought fascinates and repels me equally. Then I look back at Greco, his sick yellow face and writhing eyes and I forget everything else.

I can see Lumen is eager to start so I make quick work of the blood slide, nicking him and dragging the sharp edge down his cheek. He winces but he's too busy crying to protest.

"Don't be such a baby." Lumen hisses at him, venomous and sinister. "Crying all the fucking time." She spits the words at him, I realise that this is what he told me about Todd, how he was a pain in the ass. She uses his own words against him. She's like some poetic avenging angel. Greco tries to calm down; I can see him trying to think his way out of this. Lumen frowns, cocks her head and then removes the gauze from his mouth.

"Look, you're a woman, you won't kill me. It was an accident, what happened to Todd. I miss the boy, really I do." He squeezes every last drop of pleading, of appeal for sympathy into his voice. Lumen's lip curls. She turns to me.

"Will he be heard if he screams?" she asks, her voice barely a whisper. I shake my head; in this neighbourhood screaming won't attract any attention. She turns back to Greco. "So, scream. Scream like that poor child did as you beat him to death, when you burned him with your lighter, when you smashed his head against the wall." Greco opens his mouth, takes a deep breath, he's going to shout for his life. Lumen puts her face close to his; he lunges up at her, teeth snapping primal desperation.

"And I will afford you the exact same mercy you gave to Todd." She steps back and revs the chainsaw. Greco starts to scream and Lumen slams down the visor and grins as she cuts off first one arm and then the other.

I don't know how long he carried on screaming. Lumen sliced his legs away from his torso with six strokes, almost reminding me of Bryan with the precision of her cutting. Soon he is a mess of sinew, blood and bone. The screaming becomes a gurgle, his body unable to cope with the pain and he passes out, bubbling red at the mouth. She finishes him off and stands, her chest heaving under the bright lights, her apron slicked crimson.

When she turns to me there is still something of the predator in her expression. She throws the face mask to the ground and grabs the visor of my own and wrenches it free, snagging my hair in the tight band around the back of my head. One by one she peels the gloves from her fingers and throws them into the holdall. She is pressed against me and her heat conveys itself to my flesh in an instant. I bring my arms down her back and grab her buttocks. She allows me to lift her, wrapping her legs about me and pushing herself against me. I stagger back, meeting resistance when I meet the section of bench left clear. She grins and kisses me as I turn and place her on the plastic.

Quickly she scrambles up and removes her apron, her t shirt. Vaguely I worry about the evidence but the thought is soon gone when she reaches for her trousers. We'll have to clean up naked and bag everything in the room.

She lies back on the plastic, open and eager. A bride of Frankenstein, demon lover. I take off my clothes, savouring the way her skin is sheened with sweat and slightly pink from the contact with the blood on her clothes. Gloves, apron, t shirt, trousers until I am naked. As I lie over her I realise the irony of the situation. There have been four naked lovers lying on our plastic tonight; only two will leave this place.

She reaches down, hissing as her hands touch my hard cock. I moan, supported on my hands above her, my body taut and desperate. With one hand on the back on my neck and one between my legs she guides me to her. As I enter her she rolls her eyes, panting her breath in short bursts as though the feeling is too intense. How much she wants me is like electricity over my skin.

I groan as, inch by inch, she pulls me forward, biting her lip and growling in her throat. She is all the things I remember, fiercely tight, pressing against every inch of me with a thrilling pressure, hot and demanding. Her hips buck and I slide all the way in. I want to lie still, relish this feeling, this union but she won't let me. She brings up her feet and uses them to spur me on, pressing her heels into my buttocks as she lifts her hips. My body needs no more encouragement.

Slowly at first and then building in speed and determination we move together. I can feel the tightening in my belly and I lean back so that I can touch her with my hands, her legs still about me as I knead and pinch first one nipple then the other. I hold still for a moment while I smooth the other hand down her stomach, resting between her legs, my thumb circling her clitoris. She growls, arching back and clutching the sides of the bench.

I thrust, stifled gasps from her open mouth echoed by my growls as each movement takes us nearer. The edge rears before us, bright and sharp like a knife and we throw ourselves against it and fall together.

The cleanup is meticulous. We fold the kill room from the outside in, dragging the garbage bags with what remains of Greco and DiMarco into the yard and using the cold hose to clean ourselves, the refreshing iciness of the water is a tonic after the heat of the plastic. I put on the spare clothes I have brought and jog to fetch the car. I park it round the back of the neighbour's empty house and we neatly pack the trunk, the plastic serving as a buffer for the bags of dead meat.

We drive carefully out of the neighbourhood, no point getting stopped now. Lumen, her wet hair glittering in the street lights which are brighter as we leave the dark houses and shifty deals, puts her hand on my knee and turns on the radio. The marching band sends us cheerily on our way; she taps her finger to the drum beat.