Simon Kernick - Severed

After ten minutes, I come to a quiet, tree-lined road of expensive whitewashed Georgian townhouses. I soon find the house I want, a grand place with hanging baskets filled with flowers on either side of an imposing front door. Not the sort of place where you'd expect to run into a low-life gangster, but then, you have to remember, there's a lot of money in crime these days. Marco's address is the basement flat, which is reached via a short flight of stone steps protected by a locked, wrought-iron gate with an intercom security system. The top of the gate barely reaches my chest. I clamber over it without incident, conscious that with my holdall I must look like a burglar, and make my way down the steps and through a pretty walled garden, heavily planted with thick foliage.

When I reach the front door, I notice that there are bars on the adjoining windows. This is London after all, and if you have money, you don't want to make it easy for the area's burglars, even if the result does make your home look like a plush version of a prison cell.

I put my nose against the cool metal of the bars and find myself looking into a spacious kitchen. The worktops are empty, and the pots and pans hanging from the racks that run along the shelving units all look untouched. I move over to the front door and try the handle. It's locked. I put down the holdall, open the letter-box, and peek inside.

The entrance hall's empty, but I pick up the sounds immediately. Clear and unmistakeable as they drift through the open door of one of the rooms.

Someone's gasping for breath.

The attempts are utterly desperate, like those of an asthmatic having an attack. And they're accompanied by the sound of someone else, a man, grunting with exertion. Either it's a couple having a particularly wild bout of passionate sex, or he's trying to kill her, and straight away I know it's the latter, and that the way things are going it's not going to take him too much longer.

I unzip the holdall as fast as I can and pull out the Enforcer. I've been on enough arrest operations in Northern Ireland to know how these things work. Standing with my right side to the door, I lift it back in a low arc and then smack one end hard against the lock. Wood splinters, and the door flies open on its hinges.

The adrenalin's surging through me as I charge inside, dropping the Enforcer on the floor (it's too unwieldy to use as a weapon) and running towards the source of the noise. I've still just about got the element of surprise, and I hope this'll help as I barge my way into a bedroom where a life-size poster of Pamela Anderson in her Baywatch swimsuit smiles back at me.

A powerfully built man with dyed black hair sits with his back to me astride a young woman on a kingsize double bed, his gloved hands round her neck in a tight, savage embrace as he throttles the life out of her. The woman's legs kick wildly as she struggles beneath him, and I notice that one of her shoes, a golden open-toed sandal with a stacked heel, is missing.

Marco's already turning his head so I launch myself at him, knowing I've got to move fast. My momentum knocks him off balance and I grab him round the neck and twist hard, prepared to break the damn thing if I have to. But I've made a mistake. I should have disabled him with a throat punch, not tried to use my weight against him, because I'm always going to be at a disadvantage in this kind of struggle. Marco doesn't panic either, which is always a bad sign, and for a big man he's quick. As I force his head into the crook of my arm, pulling him backwards, he reaches round and manages to clamp a meaty hand firmly over the most sensitive and important part of my body, and squeezes savagely.

The pain is excruciating and my grip loosens, allowing him to break free and swing round so that he's facing me, his hand still firmly wedged between my legs. The good news is he's let go of the girl now, and she's still moving. It's the good-looking blonde from the brothel whose name, like a lot of other things, I have forgotten, so I guess I've now returned the favour and saved her life too, at least temporarily. The bad news is pretty obvious: I'm helpless and in agony, and by the sweaty, rage-filled expression on Marco's face, I'm guessing he's not about to let me off with a kick up the backside and a firm warning. There's death in his beady black eyes.

Trying to ignore the pain, I launch a single punch that catches him on the chin. It feels like hitting stone, and the damn thing hardly moves. His death grip on my nuts does ease a little though, but before I can fully appreciate the benefits of this I see his fist coming towards my face like an express train. It seems to take a long time to make contact, and I manage to turn my head away, but the force of the blow is still immense. There's no pain – I'm producing too much adrenalin for that – only a single, explosive shock, and then I'm sent careering backwards across the room. Thankfully, Marco lets go of my balls, otherwise I'm sure I would have been leaving them behind. I hit the wall shoulder blades first, my head quickly following suit, and slide to the floor in an ungainly heap.

I'm mildly dazed, which slows my reactions. I can only watch as Marco comes towards me, lifting a leg to launch a kick that's going to be his coup de grace. Fifteen years in the Parachute Regiment being bombed, stoned and shot at, and no-one's ever managed to put a mark on my face; and now, after all that, it's going to be an unfashionable tan-and-cream brogue doing the damage. And there's absolutely nothing I can do about it.

But the kick never comes. As I lift my hands in a feeble attempt to deflect the coming strike, Marco stumbles as the blonde jumps up from the bed and hits him with what looks like a bedside lamp. Glass shatters, and he yelps in pain. She's coughing and holding a hand to her throat, but she doesn't let this hold her back, and as Marco swings a punch in her direction she moves swiftly to one side, keeping her balance perfectly as she dodges the blow. Then, bouncing onto one foot and keeping low, she sends a vicious little karate kick into his left leg just below the knee, aiming to dislocate the joint.

Marco manages to turn his body slightly, avoiding the worst of the damage, but the kick's hurt him and there's blood running down his face from where she caught him with the lamp. And she hasn't finished yet. As he lunges for her, she stands her ground, lifts her hand, and slams a palm into the bottom of his nose.

I flinch myself. It's one of the most painful blows a fighter can deliver, and one of the most dangerous if it's done hard enough, because it can drive the bone into the brain – definitely the kind of fate someone like Marco deserves.

However, he's lucky. All he gets is a bleeding nose, but it's enough, and he really shouts this time, putting a hand over this latest injury and no doubt wondering how much it's going to cost to get it fixed. Blood seeps out rapidly from the narrow gaps between his fingers. The expression in his eyes is one of incredulity mixed with a lot of pain as he realizes that a woman half his size is taking him apart. A woman who thirty seconds earlier was pinned down and helpless on the bed.

But now he's going for something in the inside pocket of his suit, and I know it's going to be a weapon. I start to get up. The way I'm feeling I don't think I'm going to be much help, but he sees me out of the corner of his eye and it distracts him, allowing the blonde to come forward again and lash out with another kick, hitting him just below the knee.

I don't hear a crack, but it twists badly, and now Marco's deciding that whatever weapon he's carrying, it may not be enough under the current circumstances, and in one very awkward movement, he runs for the door, limping badly and making a lot of noises signifying extreme pain. The blonde grabs her shoe and something from a handbag on the floor, and a couple of seconds later I hear the front door opening and then slamming.