On the tube, going home, Eve looks surreptitiously around her. Which of the other passengers are her watchers? There would probably be two of them, both armed. The Goth couple with the Staffordshire bull terrier? The earnest-looking guys in the Arsenal shirts? The young women endlessly whispering into their phones?

She could ask to go to a safe house, but that would just be postponing the problem. The unspoken truth, as she and Richard both know, is that she must make any would-be killer break cover, and this will most easily be achieved by continuing to live in her own flat. The building and the surrounding streets, meanwhile, will be invisibly cordoned off by the protection team. If Villanelle comes anywhere near, the team will move in for a hard arrest, and if she resists, disable or kill her out of hand. One way and another, Eve knows, she's probably safer than at any time since she started working for Richard.

Dragging her keys from her bag, she unlocks the front door, and steps into the small communal hallway. Opening the door to the ground-floor flat she stands there for a moment, listening to the silence, and the faint buzz of the prosecco in her ears. Then, taking out the Glock, and ignoring the thumping of her heart, she closes the door behind her and subjects the place to a brisk and professional search.

Nothing. Collapsing onto the sofa, she flicks on the TV, which Niko has left tuned to the History Channel. A documentary about the Cold War is playing, and a commentator is describing the execution of thirteen poets in Moscow in 1952. Eve starts watching, but she can't keep her eyes open, and the documentary becomes a flickering montage of grainy black and white film and semi-comprehensible Russian. Minutes later, although it could have been an hour, the titles are rolling, accompanied by a scratchy old recording of the Soviet national anthem. Sleepily, Eve hums along:

Soyuz nerushimy respublik svobodnykh:

Splotila naveki velikaya Rus'!

Dreadful lyrics, all that crapola about an unbreakable union of republics, but a stirring tune.

"Da zdravstvuyet sozdanny voley narodov"

"Yediny, moguchy Sovetsky Soyuz!"

The will of the people. Yeah, right… Yawning, Eve reaches for the remote and flicks the TV off.

"Slav'sya, Otechestvo nashe svobodnoye…"

She freezes mid-yawn. What the fuck? Is that voice in her head? Or is it right here in the flat?

She's in the bathroom, with its faint but unmistakable echo, and suddenly Eve is devoured by a curiosity that momentarily mutes her terror. Propelling herself through the living room into the rear of the flat, gun in hand, she pulls open the door and is met by a warm, scented gust of steam. Villanelle is lying in the bath, naked except for a pair of latex gloves. Her eyes are half closed, her hair is a spiky wet tangle, and her skin is pink in the hot, soapy water. Above her feet, lying between the taps, is a Sig Sauer pistol.

The singing continues, clear and untroubled, and Eve tries to stand but discovers that her joints are gluey with fear, and her co-ordination all wrong, and she falls back onto the sofa. Somehow, the Glock is in her hand. The singing stops.

Terror stops Eve's breath. It's real. It's here. It's her.

Eve stares at her open-mouthed, her knees shaking. Registers the catlike features and the flat grey eyes, the half-healed facial cuts, the strange little twist to the mouth. "Villanelle," she whispers.

"Eve, can you come here?"

"Will you help me do my hair? I can't really manage it in these gloves."

"So you've come here to kill me?"

"What… why are you here?"

"Please." Villanelle reaches for a bottle of Eve's gardenia shampoo. "Calm down. Put your gun down there with mine."

"I read Niko's note," Villanelle shakes her head. "It's so crazy that you keep goats."

"No, I… My husband is…" Eve stares around her wildly. At the steamed-up window, the sink, the gun in her hands. She knows that she should take control of the situation but there's something paralysing about Villanelle's physical presence. The wet hair, the livid cuts and bruises, the pale body in the steaming water, the flaking toenail varnish. It's all too intense.

"You were asleep in front of the TV when I came in. Snoring, in fact. I didn't want to wake you."

"Why are you wearing those gloves?"

"Forensics."

"No, Villanelle. Please…"

"Well, then." She looks up at Eve. "You haven't got plans for the evening, have you?"

Eve doesn't move. She just stands there, the Glock heavy in her hands.

"Do you want me to?"

"I wanted to see you. It's been weeks."

"Eve."

"They're just small ones. I… I can't believe that you're here. In my flat."

"Seriously?"

"Sweetie, you keep on about this. And you're the one holding the gun."

"There's an eight-bar security lock on that front door."

Eve turns away. "I didn't imagine you. I couldn't begin to imagine anyone who's done the things you've done."

"I noticed. Quite a good one. I love your place, though. It's so… you. Everything's just how I imagined."

"Do you even know how many people you've killed? Oxana?"

"Just answer me this one simple question. Did you come here to kill me?"

"I'd like to know."

"Really?"

"OK. If I promise not to shoot you, will you do my hair?"

"You broke in. You brought a gun. So I'm guessing that you are, in fact, meaning to kill me."

She laughs. "Hey, Polastri. You really have been doing your research, haven't you? Top of the class. But let's not talk about me. Let's talk about you."

"So they say. Do we have a deal?"

"Yes."

"Eve, please, don't spoil everything." Villanelle tilts her head flirtatiously against the edge of the bath. "Am I how you imagined me?"

"You're insane."

Eve frowns. Finally she nods, lays down the Glock, rolls up her sleeves, slips her watch into her pocket, and reaches for the shampoo.

When she's done, she drapes a towel over Villanelle's head, twists it into a turban and picks up her Glock. "So what do you really want from me?" she asks, jabbing the end of the barrel into the base of Villanelle's skull.

Touching her is strange. And running her hands through her slick, wet tresses is stranger. Eve washes Villanelle's hair as if it's her own, caressing her scalp with dreamily circling fingers, probing and pressing and inhaling her biscuity, gardenia-scented smell. And then there's the fact of Villanelle's nakedness. The small, pale breasts, the lean musculature, the dark crest of pubic hair.

Testing the water temperature on the back of her hand, Eve rinses Villanelle's hair with the shower head. If you know that you're being manipulated, she tells herself, then you aren't. Inside her, something has shifted. Something has tilted her world on its axis.

"I put some champagne in the fridge. Could you open it for us?" Villenelle yawns, baring her teeth. "I unloaded that thing, by the way. And the Sig."

"I thought you were worried about forensics?"

Abruptly standing up, Villanelle stretches, revealing unshaved armpits. Then she reaches across to the medicine cabinet, takes out a pair of scissors, removes her gloves, and starts cutting her fingernails into the grey bathwater.

"I'll deal with it. And talking of forensics, I could really use some clean pants."

"I forgot. Sorry."

"No, I've got lots, but they're all the same."

"If you tell me why you're really here."

When Eve returns, Villanelle is wrapped in a towel, gazing at herself in the mirror. Eve throws her the pants but Villanelle, absorbed in her reflection, doesn't notice, and they land on her wet hair. Frowningly, she lifts them off. "Eve, these are not very pretty."

"Couldn't you have brought some with you?"

"Yes."

"Jesus, Villanelle."

"You have only one pair?"

"Knickers?"

"Tough. They're all I've got."

Eve checks both weapons. It's true.

For a moment, Villanelle appears to wrestle with this concept, then she nods. "So will you open the champagne now?"

"Have you got any nice dessert in the fridge?" Villanelle asks. "Something that will go with this champagne?"

"There's ice-cream cake in the freezer compartment."

"You fucking get it."

"Can you get it?"

Wordlessly, Eve does as she's been asked, and then, turning back from the fridge, sees Villanelle raise the pistol and turn towards her. Her mind emptying, Eve sinks to her knees and squeezes her eyes closed. A long silence roars in her ears. Slowly, she opens her eyes to discover Villanelle's face inches from hers. Eve can smell her skin, the wine on her breath, the scent of shampoo. With shaking hands, she gives Villanelle the frozen cake.

Leaning against the wall in the living room with a glass of pink Taittinger champagne in her hand, Villanelle looks poised, efficient and feminine. Her dark blonde hair is slicked back neatly from her forehead, and her outfit -- black cashmere sweater, jeans, trainers -- is chic but forgettable. She could be any smart young professional woman. But Eve can sense her feral aspect, too. The potential for savagery that beats like a pulse beneath the urbane exterior. It's a barely perceptible murmur, right now, but it's there.

The midwinter gaze meets hers. "Because you need me, Eve. Because everything has changed."

"Eve, kotik, I'm your guest." She takes her Sig Sauer from the waistband of her jeans. "And this time the gun's loaded."

"It's beautiful."

"Trust you?" Slowly, Eve stands. Villanelle has put the automatic down on the dining table. It's within easy reach. One good lunge, and… she's hardly even formed the thought when Villanelle catches her across the face with a stinging backhand slap. Breathless with shock, Eve staggers towards the sofa and sits down.

Eve looks at her. Notes how Villanelle mirrors the way she sits, the way she carries her head and neck, the way she holds her glass. If she blinks, Villanelle blinks. If she moves a hand or touches her face, so does Villanelle. It's as if she's learning her. As if she's occupying her, inch by stealthy inch, slithering into her consciousness like a snake.

"Fuck you," Eve mouths, the side of her face throbbing painfully.

"No, fuck you, suka."

Villanelle gathers up the glasses and champagne bottle, and deposits herself beside her on the sofa. "Come on, let's talk. For a start, how was the bracelet? Did you like it?"

They stand there, face to face, then Villanelle reaches out a hand and touches Eve's cheek. "I'm sorry. I didn't mean to hurt you."

"I said. I need you. To trust me."

"So… what do you say?"

Probing her teeth with her tongue, tasting blood, Eve shrugs.

"Eve, listen. I need you to trust me, OK?"

"You don't remember?"

Eve peers at it. He's about thirty, lean and sunburned, wearing a khaki T-shirt and the sand-coloured beret of the Special Air Service. The photographer has caught him in the act of turning, his eyes narrowed in annoyance, with one hand raised, perhaps to shield his face. Behind him are the unfocused outlines of military vehicles.

"That's probably not a good idea," says Villanelle. "But whatever." Taking her phone from her pocket, she retrieves an image and shows it to Eve. "Have you ever seen this man?"

Eve reloads the Glock, and, uncertain what to do with it, pushes it into the back waistband of her jeans, where it lodges uncomfortably.

"You're insane."

"You killed Simon Mortimer," Eve says. "You almost hacked his head off."

"No I'm not, Eve. I'm just you without the guilt. Cake?"

"Simon… Was that the one in Shanghai?"

"That was heaven," Villanelle murmurs, putting her bowl on the floor. "Now I need you to listen to me very carefully. And before I forget" -- she pulls a dozen 9mm rounds from her jeans pocket and hands them to Eve -- "these are yours."

For several minutes they sit there in silence, spooning ice cream, chocolate chips and frozen cherries into their mouths.

Villanelle shrugs. "What can I say? It must have seemed like a good idea at the time."

"I know him as Anton. He used to command E Squadron, who handle black operations for MI6, and now he's my controller. On Thursday he ordered me to kill you."

"Because you've got too close to us, and by us I mean Dvenadtsat, the Twelve. When Anton gave me the order, I was in a private hospital in Austria. He came to see me in my room, and when he left the hospital, he drove away with this man. That's Anton on the left."

"No. Who is he?"

"Why?"

The image is tilted and poorly framed, but clear enough. It's taken from inside a building, looking down on a snowy car park. Two men are standing by the passenger door of a silver-grey BMW. The left-hand figure, in a bulky black jacket, has his back to the camera. Opposite him, clearly recognisable in an overcoat and scarf, is Richard Edwards.

Eve stares at the image for a long while without speaking. Inside herself she feels the collapse of all her certainties, like an iceberg imploding into the sea. This man, who just hours ago was pouring her prosecco in a pink linen shirt, and telling her that she was "born for the secret life", has agreed to, and perhaps even demanded, her death.

"Chloe, it's Eve. I wanted to ask you something about our conversation this afternoon. Confidentially."

"I need to make a call," Eve tells Villanelle, and, searching the detritus of her bag for Chloe Edwards's card, she calls the number. It rings for almost ten seconds, and then Chloe answers. She sounds as if she's been asleep.

"That Russian guy you were talking about."

Tikhomirov guessed. That moment when she asked him whether Richard had mentioned their suspicions about Yevtukh's disappearance. Just for a second, the FSB officer's eyes widened, as if he'd suddenly understood something that had eluded him for ages. That's when he asked her about the canary. She pictures the bird, singing in its cage, far underground. The deadly, odourless gas wreathing through the seam, and the canary silent now, a stiff little mess of feathers.

"Oh hi, Eve. Yeah, um…"

"Was his name by any chance Konstantin?"

"Old friend. I'll introduce you one of these days."

"Er… Yeah! I think it was. Wow. Who is he?"

"That'd be cool."

"Uh-huh."

"Just don't mention to your dad that I called, OK?"

Eve disconnects and lays the phone gently on the table. "Oh, God," she says. "Oh my God."

"No. They don't tell me things like that. Of course I knew you worked for Edwards, but it wasn't until I saw him with Anton in Austria that I understood how you'd been set up."

""Kay."

"Every time I discovered anything I'd report it to Richard, he'd pass it on to the Twelve, and they'd patch the vulnerability. All I've been doing, all these weeks and months, is making them stronger. Jesus wept. Did you know?"

"I'm sorry, Eve."

She stares at Villanelle. "I thought I was hunting you down for MI6, but in reality I'd been set up by Richard to test the Twelve's defences. I was the canary in their mine."

Eve nods, coldly furious with herself. She's fallen for a classic false flag operation, constructed, like all the best deceits, around her own vanity. She thought she was so clever, with her intuitive leaps and her left-field theorising, whereas in truth she was just a skilfully manipulated dupe. How could I have been so obtuse? she wonders. How could I not have seen what was happening right before my fucking eyes?

Villanelle says nothing.

"Two reasons. When he ordered me to kill you, I realised that it was because you'd found out too much about me. Which meant that I'd be the next one to die."

"You liked it though, didn't you?" Villanelle says. "Playing the secret agent in your secret Goodge Street office with your secret codes, which weren't secret at all."

Looking at her undrunk wine, Eve feels a vast weariness. "So what happens now? I know this sounds weird, but why haven't you shot me or whatever, like Anton said?"

"You are a player, sweetie. Any time I was bored, I'd log on and read your email. I love that you spent so much time thinking about me."

"Yes, at Fontanka." She looks pensive. "And now one of my people has been arrested in Moscow."

"Richard flattered me, and it worked. I wanted to be a player, not just some paper-pusher at a desk."

"Because you were compromised?"

"Exactly. The Twelve don't take any chances. I saw that with Konstantin, who you obviously know about. He was my handler before Anton. They thought he'd talked to the FSB, which was bullshit, and they… had him killed."

"At Fontanka."

"Well, the FSB have got Lara now. She's in Butyrka."

"Larissa Farmanyants. Your girlfriend."

"It means that he'll have me killed, as soon as he can. I imagine his plan is to wait until I've finished with you, then deal with me."

Villanelle looks at her. "Really? You haven't worked that out yet?"

"Yes, and I'll tell you why. I know that Lara was arrested, because she managed to send me an emergency message. And then when I saw Anton earlier today he spoke about Lara, but didn't say a word about her being arrested. He knew that I'd know what it meant."

"Lara, yes, although she wasn't so much a girlfriend in the holding hands and kissing sense. With us, it was more just sex and killing."

"You're certain about this?"

"You said there were two reasons you haven't killed me. What's the second?"

"What does that mean?"

"Putain. That's bad. They'll definitely interrogate her, so I'm doubly burned as far as Anton's concerned."

Eve shakes her head.

Eve stares at her, the complexity, strangeness and sheer enormity of the situation suddenly bearing down on her. "So what happens now? I mean, what…"

"Because it's you, Eve."

"What do we do? How do we get out of this alive?"

"You need to understand two things. First, that the only way of surviving is if you and I work together. You have to put your life in my hands, and do exactly, and I mean exactly, what I say. Because if not, the Twelve will kill you, and me too. There's nowhere to hide, and no one you can trust to protect you except me. You have to take my word for it that this is true."

"Yes."

Villanelle begins to pace the room, her movements as fastidious as a cat's. Occasionally she darts a glance at a book or a photograph. Catching sight of her reflection in the mirror over the fireplace, she comes to a halt.

"You have to accept that your life here is over. No more marriage, no more flat, no more job. Basically, no more Eve Polastri."

"So…"

"She dies. And you leave all this behind. I take you into my world."

"And the second thing?"

Villanelle hitches up the sleeves of her sweater. Her hands are strong and capable. Her eyes, all business now, meet Eve's. "The first thing we have to do is convince Anton that I've killed you. Once he thinks you're dead, we've got a very short breathing space before he comes after me. We have to misdirect him, and whoever he sends. Then we disappear."

Eve stares at Villanelle. She feels as if she's in free-fall, weightless.

"Eve, you still don't get it. They have people everywhere. There's no police cell, no prison, no safe house that they can't get to. If we want to live longer than twenty-four hours, we have to disappear."

"And what do you mean by that?"

Eve closes her eyes. "Look," she says desperately. "Let me contact someone I know in the police. DCI Gary Hurst. He was involved in the Kedrin investigation. He's a good guy, and completely straight. He'd put us under full close protection, and I'm sure you could do some sort of a deal, testifying against the Twelve in exchange for immunity. I'd much rather go that route."

"Like I said, another world. Mine."

"Where to?"

"Not any more. The Twelve are the establishment now. You know what the assassination department is called? Housekeeping."

Eve stands up and starts to walk around in tight circles. She's still in free-fall, plummeting down some endless lift-shaft. She can feel the barrel of the Glock rubbing sweatily in the cleft of her buttocks. Pulling the gun from her waistband, she holds it loosely in her right hand. Villanelle doesn't move.

"I mean the world that's all around you, but which is invisible if you're not part of it. In Russia we call it mir teney, the shadow world."

"Surely that's the Twelve's domain?"

"And there's no alternative?"

Eve narrows her gaze. "What happened here?" she asks, reaching out and touching the scar on Villanelle's lip.

Eve nods, and continues to pace. Then, quite suddenly, she sits down again.

"Give me that," says Villanelle, gently taking the Glock.

"I'll tell you. I'll tell you everything. But this isn't the time."

She looks into the waiting grey eyes.

"Not if you want to stay alive."

"Niko would think I was dead?"

"Everyone would."

On the dining table, Villanelle places the medical supplies from Whitlock and Jones, and from her backpack takes a bin bag, a tin of Waitrose dog food, a white porcelain cup, a plastic belt, a tin of modelling wax, a small glass dropper of spirit gum, a fountain pen, a packet of hair-grips, a face powder compact, an eye-shadow palette, a comb, several condoms, her Sig Sauer automatic and suppressor and Eve's Glock.

Eve nods. Time rushes almost audibly past her ears. There's the world that she knows, the world of work, alarm calls, email, car insurance and supermarket loyalty cards, and there's mir teney, the shadow world. There's Niko, who loves her, and is the kindest and most decent man she has ever met, and there's Villanelle, who kills for pleasure.

"OK," she says. "What do we do?"

A little apprehensively, Eve does as she's bidden. From the table, Villanelle takes a cannula, a hollow blood collection needle. The cannula has a twistable port and a clear PVC transfer tube attached. Villanelle feeds the open end of the tube into a condom, holding it tightly in place with an elastic hair-grip. Taking the plastic belt, she tightens it around Eve's bicep until the vein in her forearm is bulging, and then, surprisingly gently, slips in the cannula and opens the port.

"OK, the first thing I need is some of your hair. I'm going to pull it out." She does so, Eve winces, and Villanelle smiles. "Now I need a dark sheet. Darkest you've got. Quickly, while I set everything up."

"Squeeze your fist," Villanelle tells her, as blood flows through the PVC tube and begins to fill the condom. After a few minutes, it holds two-thirds of a pint of Eve's blood, and Villanelle turns off the port, and detaches and knots the condom.

Taking herself to the bedroom, Eve returns with a folded dark blue bedsheet, which Villanelle places on the table with the other items. She's turned the TV on, and is streaming a noisy Japanese cop show. "Sit," she orders Eve, pointing to the sofa. "Pull up your sleeve."

Villanelle regards her work with a critical eye, then moves back to Eve. Taking a pinch of modelling wax, she rolls it into a marble-size ball, flattens it, and glues it to Eve's forehead with spirit gum. Then taking the cap off the fountain pen, she presses the circular end into the low mound of wax, cutting a neat hole through to the skin. With the face powder, she blends the wax into Eve's forehead, fills the hole with black eye-shadow, and surrounds the raised area with bruise-coloured purple.

"You're going to have such a pretty entry wound," she tells Eve. "But now I need more blood. It's going to leave you feeling a bit weird, OK?"

Picking up the Sig Sauer, Villanelle walks to the centre of the room, then, holding the sagging condom over the carpet, she fires a single, downward-angled shot into its dark, distended belly. There's a wet smack, and an outward burst of blood. From the centre of the carpet, a shining red spatter fans outwards towards the window, shading into a myriad of fine droplets which gleam on the floor and furniture and walls.

Eve is very pale. "I think I'm going to pass out," she whispers.

This time she takes two condoms of blood, another full pint.

"I've got you," Villanelle says. Placing an arm around Eve's shoulders and another under her knees, she lays her on her side on the carpet, with her head at the epicentre of the blood spray. Carefully spread-eagling her limbs, she places the Glock in her right hand. "Don't move," she says. "I've got to work fast before the blood clots."

Villanelle drops the porcelain cup into the Waitrose shopping bag, and swings it against the dining table so that it shatters, Then, opening the dog-food can, she empties its contents into Eve's hair, at the back of her head, and carefully arranges half a dozen of the larger pieces of shattered porcelain in the gelatinous mess. Satisfied with the composition, she pours the first condom of blood on top, dotting a scarlet forefinger into the cosmetic entry wound. The contents of the second condom form a dark lake behind Eve's head.

Eve flutters her eyelids in response. She's swimming in and out of consciousness now. The room is shadowy and insubstantial and Villanelle's voice is muted, as if it's coming from far away.

Taking out her phone, Villanelle photographs her from various angles and distances, checking the pictures until she's satisfied. "Done," she says eventually, and performs a little dance of pleasure. "That looks so great. The jelly in the dog food is just perfection. Now I'm going to clean you up. Don't move."

This takes very little effort on Eve's part.

She runs the comb through Eve's hair, dragging out the already congealing blood and offal. Then, having put the Waitrose bag over Eve's head, and propped her up against the sofa, she scrapes the porcelain fragments and the remainder of the dog food from the carpet with a kitchen spoon, depositing it in the tin, and the tin in the rubbish bag. With it go the cannula and tube, the remains of the condoms, the comb, the eye-shadow and powder, the spirit gum and wax, the belt, the pen and the hair-grips.

"OK. Look dead."

Taking the hair she's pulled from Eve's head, Villanelle sprinkles it in the congealing blood, which she then smears across the carpet with a swipe of her hand. She peels off the latex gloves and drops them in the bin-bag then pulls on a new pair. "Your turn for a bath," she announces, scooping Eve up in her arms.

"I know. I took a lot of your blood. But look what I'm sending to Anton."

Eve takes Villanelle's phone. Notes with awe her own chalk-white features, half-closed eyes and gaping mouth. Just above the bridge of her nose, there's a purplish crater around a blackened 9mm entry wound. And at the back of her head, a chaotic horror of skull fragments, the bone shining whitely through the red, and a slick porridge of destroyed brain matter.

Lying semi-conscious in the warm water as Villanelle rinses her hair, Eve feels a vast sense of peace. It's as if she's between lives. Half an hour later, dried and dressed in clean clothes, she sits on the sofa drinking sweet tea and eating slightly stale chocolate digestive biscuits. She's crushingly tired, her skin is clammy, and the smell of blood is thick in her nostrils. "This is the definitely the weirdest I've ever felt," she murmurs.

"I know. Your friend Lara blew an old man's brains out in the metro, aiming for me."

"Fuck. I really did die, didn't I?"

"I've seen headshots up close," Villanelle says delicately. "It's accurate."

"No. That's the thing about being dead."

"It's a van, in fact. Give me that mug and biscuit wrapper."

"Just wondering."

"Mightn't people see?"

"Can I take anything with me?"

"You've got a car?"

"Don't wonder. Get your strength back. I'm going to tidy up and pack the car."

"Why do you ask?"

"I suppose it is."

"Aren't you upset about her?"

"I'm really shocked she missed. And then to be picked up by the FSB and thrown into Butyrka. That's such a shitty day's work."

"OK," she says. "Time to go. I'm going to wrap you up in this sheet, cover you with a folded rug and carry you out over my shoulder."

Five minutes later, Villanelle surveys the flat. The place is as she found it, except for the bloody tableau in the main room, which looks just as she planned. She's particularly pleased with the clotted red-brown smear on the carpet, suggesting a bled-out corpse dragged away by the legs. As to what narrative will be constructed around this, she doesn't care. She just needs time. Forty-eight hours will do it.

"Doesn't matter if they do, they'll just think it's someone moving their stuff. Later, when the street's full of police cars, they might see it differently, but by then…" Villanelle shrugs.

In the event, it's accomplished very quickly, and Eve marvels at Villanelle's strength as she lowers her, apparently without effort, onto the floor of the panel van. Mummified in the blue sheet, with Villanelle's rucksack jammed beneath her head, she hears the van's rear doors close and lock.

It's not a comfortable journey, and the first half-hour is made worse by a succession of speed bumps, but eventually the road levels out and the van picks up speed. For Eve, it's enough just to lie there, seeing nothing at all, in a state that's not quite wakefulness and not quite sleep. After what might have been an hour, but might equally have been two, the van comes to a halt. The doors open, and Eve feels the sheet unwrapped from her face. It's dark, with a faint wash of street lighting, and Villanelle is sitting on the tailgate of the van, her rucksack over her shoulder. Leaning inside she unbinds Eve from her winding sheet. Outside it's cold, and smells like rain. They're in a car park beside a motorway, surrounded by the dim forms of heavy-goods vehicles. An illuminated shack announces CAFÉ 24 Hrs.

When they leave, Eve feels transformed, if a little nauseated. She follows Villanelle across the car park, and then, mystifyingly, along a darkened path towards a sparsely lit residential block. At the foot of a tower, Villanelle inserts a key into a steel-fronted door. They climb an unlit stairway to the third floor, where Villanelle opens another armoured door, and turns on the light. They're in an unheated studio flat, furnished with bleak austerity. There's a table, a single chair, a military canvas-topped camp bed, a khaki sleeping bag, a cloth-covered wardrobe with a hanging rail full of clothes, and a stack of metal storage boxes. Insulated blackout curtains prevent the escape of light.

Five minutes later, steaming mugs of tea and two of the biggest, greasiest burgers that Eve has ever seen are placed in front of them.

Villanelle helps Eve out of the van, and they pick their way over the puddled ground. Inside the café, beneath the lunar glow of strip lights, a dozen men are silently addressing plates of food at plastic-topped tables as Elvis's "Are You Lonesome Tonight?" issues from ancient wall-mounted speakers. Behind a counter a woman in a rockabilly ban-dana is frying onions on a hotplate.

"Don't worry. I'm starving."

"Eat," Villanelle orders. "All of it. And all the chips."

"It's mine. A woman needs a room of her own, don't you think?"

"Enough questions. The bathroom's there, take what you need."

"What is this place?" Eve asks, looking around her.

"But where are we?"

The bathroom proves to be a concrete cell with a toilet, a basin and a single cold tap. A plastic crate on the floor holds a jumble of toiletries, tampons, wound dressings, suturing kits and painkillers. When Eve comes out, the sleeping bag has been unrolled on the camp bed and Villanelle is field-stripping and cleaning her Sig Sauer at the table. "Sleep," she says, not looking up. "You're going to need all your strength."

"What about you?"

"Five p. m. You've been asleep for fifteen hours."

"I'll be fine. Go to bed."

Eve wakes into a cold and unidentifiable twilight. Villanelle is sitting at the table in the same position, but she is wearing different clothes and slowly scrolling through maps on a laptop. Slowly, wonderingly, Eve's memory recreates the events of the previous day. "What's the time?" she asks.

They step outside into a desolate, twilit landscape. Eve looks about her. It's the sort of place she's driven past countless times without really seeing. The building they've just left is a condemned tenement block. Metal shutters cover doors and windows, security notices warn of patrolling guard dogs, wild lilac bushes have grown through the forecourt's littered tarmac. Mir teney, the shadow world.

"Oh my God." She unzips herself from the sleeping bag. "I'm starving."

"Good. Get ready and we'll go and eat. I've put out new clothes for you."

When they leave the café the drizzle has become rain. On the motorway, the traffic is unceasing, zipping by in a grey, vaporous spray. Eve follows Villanelle past the building where they stayed the night, to a graffiti-tagged row of garages. The end garage is secured with a galvanised steel roller-door and a heavy-duty coded padlock, which Villanelle unlocks. Inside, it's dry, clean and surprisingly spacious. A hydraulic motorcycle repair bench runs along one wall; against the other, a shelved unit holds helmets, armour-panelled leather jackets, trousers, gloves and boots. Between them a volcano-grey Ducati Multistrada 1260 waits on its stand, fitted with locked panniers and top-box.

"Everything's packed," Villanelle tells Eve. "Time to get dressed."

They put on their helmets, and mount the Ducati. The whisper of the Testastretta engine becomes a murmur, the headlight beam floods the darkness. Villanelle takes the slip road slowly, allowing Eve to find her balance and settle tightly against her. She waits for a gap in the traffic, the murmur builds to a snarl, and they're gone.

"Ready for this?" Villanelle asks, zipping up her jacket, and Eve nods.

Five minutes later she wheels the Ducati out of the garage, and waits while Eve pulls down and locks the roller door. The rain has stopped, and for a moment the two women stand there, facing each other.