We have two nights left on the North Sea platform, then we return to Russia. At least I'm assuming that that's the case, as my passport contains no visa for any other country. Over the course of the day, I run through possible ways of contacting Tikhomirov. My only chance to do this will be when we've landed in Russia, and are making our way through the border controls. It will be impossible beforehand, while we are under the eye of Anton, and almost certainly impossible afterward.

The next day passes swiftly. I speak only when spoken to, ignore Oxana completely, and limit my exchanges with Charlie to calling the shots for them.

I consider different scenarios. A diversion of some kind, in the course of which I throw myself on the mercy of customs or security officials. A medical emergency, perhaps, with me writhing on the arrivals' hall floor with simulated gastroenteritis. Could I carry that off? Unlikely. Anton will be looking out for any hint of weird or erratic behavior. He will keep us on a very short leash, and he's undoubtedly practiced in dealing with the kind of functionaries you find at Russian airports.

We've been working our way through our evening meal for the best part of fifteen minutes when I realize what's happening right in front of my eyes. Anton's watching us from the head of the table, and making entries in a small spiral notebook.

He's writing. With a pencil.

When he's finished Anton shoves the notebook in his trouser pocket and tosses the pencil onto a worktop, between a box of plastic spoons and a glass jar filled with teabags. Looking up, he catches my eye, and we exchange tight, non-committal smiles. Neither of us has quite worked out how we should conduct ourselves with each other. He's tried to have me killed at least twice, and I've never disguised the fact that I find him repulsive. It's not the ideal basis for a relationship.

Maybe I could try to steal a phone? The passport queue would be a possible place to lift one from a fellow traveler's back pocket or bag. All I would have to do would be to input Tikhomirov's number and let it ring. He would know it was me and be able to identify my location and track the phone. The penalty if I was discovered, however, would be severe, and given how closely we would all be watched, discovery was the probable outcome.

I glance at the pencil. It's almost hidden behind the cardboard spoon-box, and as I look away a plan comes to me fully formed. It's dangerous, so dangerous that I can't bring myself to think of it in too much detail, but it's all I have. And weirdly, it brings me a sort of peace.

Sliding out of my bunk in combat clothes and socks, I open the door inch by inch, terrified that a squeak of hinges will betray me. Outside the cabin it's dark, but I've learned the layout. I'm on a small landing, inside one of the platform's cylindrical legs. Bolted to the wall opposite me is a ladder, which runs upward to the deck and downwards to the level of the sea. Below me is Ginge's cabin. Above me is Anton's. I've got to get past his door without him hearing me if I'm to get to the deck.

Taking a deep breath, I begin to climb the ladder. My socks are slippery on the cold steel rungs, and I can feel my heart pounding fearfully in my chest, but I force myself to keep going. There's no sound from Anton's cabin. I move upward, and now I can hear the faint hum of the generator that provides the platform with power; it's housed in a hut next to the canteen.

As I haul myself through the hatch onto the platform deck, a gale-force wind whips my hair into my eyes. Above me the sky is a streaky blue-black, around me the sea is a roiling gray, faintly illuminated by the warning lights at each corner of the platform. I crouch there for a moment. I can no longer hear the generator, only the scream of the wind and the crashing of the waves. Then, keeping low, I run to the canteen and close the door behind me. Inside it's quieter, but no less cold. A couple of steps take me to the worktop, and I reach around the box of spoons for the pencil.

A moment later it's in my hand, and just as I feel its hexagonal shape between my fingers the door swings open and a torch shines in my face. The shock is so great that I stop breathing, and stare open-mouthed into the light.

"You deceitful cunt," Anton says. "I knew I was right about you."

I can't see his face behind the torch beam, but I can imagine the sneer. There's no way I can escape. He's standing between me and the door.

"You were going to try and get a message out, weren't you? You saw me writing notes with a pencil and you thought, I'll have that. Well you know what, you dumb dyke, that's exactly what you were supposed to think. I left the pencil there knowing you'd come looking for it. You fucking women, honestly."

I continue to pull away from Anton with all my strength, grunting with the effort, and then I jump forward, unbalancing him so that he falls heavily backward and cracks his head on the steel door jamb. As he lies there, half-stunned and blinking in the raking torch beam, I shove the pencil as hard as I can up his left nostril.

"I wish I'd saved everyone's time and killed you in St. Petersburg. You and your psycho girlfriend. But hey, better late than never." He reaches out with his free hand and grabs my arm, wrenching me toward the open door. I resist, pulling back hard, and as I do so I have the surreal impression that my body has been occupied by someone else. Someone strong, and ruthlessly efficient. Someone like Oxana.

Waves of fury wash through me. I feel weirdly focused and light-headed.

Anton's eyes widen, his fingers writhe, and a quavering sound issues from his throat. He tries to lift his head, but I keep hold of the protruding end of the pencil and push downwards, forcing it further and further up his nose. The pencil sticks fast after about ten centimeters, so I put my weight behind it, and it slips in another couple of centimeters. Taking the torch from Anton's hand, I shine it in his face. His eyes have rolled back into his head, his lips are fluttering, and a worm of blood is crawling from his open nostril into his mouth.

"It'll wait. Just hold his legs while I give it one last bash."

I drop the book with a shriek, and clutch my heart. "Jesus, Oxana."

"Definitive, according to the Observer."

"What are you doing?"

"Eve, sweetie, what's going on?"

"Is that good?"

"I don't understand."

When Anton finally stops shuddering I subside to an exhausted crouch against the container wall.

"No, that you're killing Anton. Was he annoying you?"

"Fucking women," I murmur. "What can you do, eh?" The point of the pencil has almost certainly penetrated Anton's brain, but not lethally. I need something hard and heavy. "Stay there," I order him, and shine the torch around the canteen. Lying on the bookshelf is a substantial hardback volume. I'm reaching for this, when Anton half-rises to his feet, his eyes staring wildly. Grabbing the book with both hands I draw it back, take aim, and smack the pencil in another inch. He sinks to the floor, his legs moving feebly.

"He caught me stealing the pencil."

"What the fuck does it look like I'm doing? Hammering a pencil into Anton's brain with a copy of Birds of the North Sea."

"Is he dead?" Oxana asks, flicking the end of the pencil with her finger.

"In that case help me, because I need to get rid of this body? Over the edge of the platform."

"Because I love you."

Oxana gives a long, phlegmy sniff. "You really are quite the player, aren't you, pupsik?"

"I don't know. I just…" She sniffs again. "Truthfully?"

"I was looking for you. I went to your cabin and you weren't there."

"I don't want to know what you did, I just want to know why you did it."

"Charlie's not you."

"So why did you fuck them?"

"Tough shit. Go and bunk up with Charlie."

"God, Oxana. Please."

I can't see much, but I can feel the warm bulk of Anton's body against my feet.

"Why?"

"Why were you looking for me?"

"Truthfully."

"Because I was angry with you."

"I do. Truly."

"Tell me why you're here."

"I missed you."

She hunkers down opposite me, reaches for the torch, and switches it off. "Night vision," she explains.

"Well, technically speaking I didn't. We --"

"Near enough."

"OK, pupsik. Shall we take a leg each?"

I've forgotten that securing the pencil was the point of the whole exercise. I nod and, kneeling beside Anton, try to pull it out of his nose with my fingertips. Anton's eyes roll in his head but I can't budge it, it's stuck tight.

"Sor-ree…" She glances at Anton. "And you can stop looking at me like that, Pinocchio."

"So do it."

"Yeah, I know. Fuck."

"That's a really disgusting idea."

"You're the one that wants the pencil, babe."

"Do you still want that pencil?" Oxana shouts, as the wind screams in our ears.

We do it. Oxana locks her fingers under Anton's jaw, and I lean sideways into his face and close my teeth on the end of the pencil. His lips are dry, his stubble rasps against my cheek, and his breath, now coming in shallow gasps, smells of brandy and curry. I pull at the pencil as hard as I can, but it doesn't move, and I'm afraid of snapping the end off with my teeth. Eventually I lift my head, gagging, and drag sea air into my lungs.

Oxana tries, but does no better. She looks at me. "The only way we're going to do this is if I hold his head, and you take the end of the pencil between your teeth and pull it out."

"It was just a sex thing."

"Sex things with other people are not OK, Oxana."

"Don't call me that. I haven't forgiven you."

It takes us several minutes to drag Anton out of the canteen to the westward end of the platform.

"Again," Oxana mouths.

I take the pencil in my teeth again, brace my hands against Oxana's biceps and pull as hard as I can. This time I feel something yielding. The pencil moves a millimeter or two, and as it finally slides out I feel liquid warmth bathe my neck and chest.

"You want a try?" I shout at her, and she shakes her head.

"Fuck," I say. "Blood everywhere."

"Don't worry, sweetie, we'll deal with it. Sit back to back with me so I can kick this asshole over the edge."

I feel her shoulders tense as she shoves with her legs, and when I look round Anton is gone. I don't even hear the splash.

We spend the next ten minutes tidying up. While I wash off the worst of the blood with water from the canteen, Oxana creeps into Anton's room and finds me a clean T-shirt and combat shirt. I pull these on, then we locate the Napoleon bottle, which is still half full, and take it outside. Oxana pours the remaining brandy over the edge of the platform, and leaves the empty bottle standing on deck. I knot my bloody clothes into a bundle and, using the torch as a sinker, throw them out to sea. Then, with the night's work completed, we depart the deck. Behind me, Oxana closes the hatch.

"Your cabin's in the south leg," I tell her, but she takes no notice. Silently, rung by rung, she follows me down the steel ladder, past Anton's empty cabin, to mine. I turn on the light, we stand there for a moment, and then I pull back my arm and punch her in the mouth, as hard as I can. She flinches, blinks a couple of times, spits blood and snot into her hand, and wipes it down the thigh of her combat trousers.

I shake my head, wanting to hit her again, but discover that I'm shaking so much that I can't. I try to speak, but I can't do that either, because she's pulled my face down into the warm place between her shoulder and the slope of her breast, and has locked me there so tightly, with her cheek sealed against my forehead and her hand in my hair, that I can hardly breathe.

"Are we?" she asks, sniffing loudly in my ear, and all I can do is nod. She holds me for a time, and then lifts my face opposite hers.

"It didn't mean anything," she says. "It was just sex."

"So," she murmurs, licking her lips. "Are we even now?"

She narrows her gray cat's-eyes at me.

"Have you?"

"I've got a cold, Eve. It happens. Even to Russians."

"No. Do you need one?"

She draws an imaginary zip across her mouth, but her lips are twitching.

"I'm sure we won't. And it doesn't matter if we do, anyway, now that Anton's gone?"

"Then have one now."

"And just for the record, have you had a shower since fucking Charlie?"

"Like I said, I didn't actually --"

"It was a shitty thing to do. Really nasty."

"Eve, it's fuck-knows-what in the morning. I'll wake Ginge up."

"No, but you do. That sniffing and swallowing thing you do is really gross."

We allow ourselves two luxurious minutes under the hot water. The first to wash off everything that's happened, the second to begin rediscovering each other. The tiny washroom is not the ideal space for a date, but it's warm and steamy, and Oxana is strong. Strong enough to lift me up the wall until her face is between my thighs and my legs are over her shoulders and I'm leaning back, open-mouthed and gasping, against the wet tiles.

"I'm joining you. I feel disgusting."

"No."

"We?"

She reaches into her pocket, pulls out a crumpled pair of knickers, and blows her nose into them. "OK. Done."

"So do something about it. Jesus."

"Just don't speak, OK?"

"Do you have a tissue?"

"I know."

"And was it? Is it?"

In my narrow bunk, with her body warm against mine and the smell of her in my nostrils, we huddle under the thin blankets and swap recollections of our first encounters.

"It was that hot, thundery evening in Shanghai," she whispers. "We just saw each other for a second in the street, but it was electric. It was like looking at myself. That's why I climbed into your room at the hotel and watched you sleep. To make sure it was true."

"I'll tell you tomorrow. I don't want to think about all that. I want us to be here, in this bunk, in this cabin, forever."

"One day."

"You know the answer to that. You proved it tonight. Are you going to tell me why you wanted that pencil so much?"

"I know, pchelka, me too. One day."

"Spoki noki, baby bee."

"Sweet dreams."

When Anton doesn't show up for breakfast the next morning, no one takes much notice. The empty brandy bottle at the edge of the platform has been noted, and Nobby and Ginge make sympathetic references to hangovers and mornings after. By eight-thirty, however, the two men are looking at their watches and exchanging concerned glances. Ginge offers to go to Anton's cabin and wake him, and when he returns he looks grave.

"Nah. Why would he? He was well up for this project and obviously wanted to see it through. Probably got pissed up and lost his footing. Easily done."

"Only possible conclusion, he went over the side," Nobby says. "Probably after downing that bottle."

"Deliberately?" I ask.

"I can be your spotter today," Nobby says.

Ginge nods. "Question is, what do the rest of us do now? We've got twenty-four hours until the chopper comes to pick us up."

He and Nobby confer, then we split up and search every inch of the platform. It doesn't take long. The two office containers are locked, but a glance through the windows tells us they're unoccupied.

"Sure. Whatever."

"No. And even if there was, it was blowing at least force eight last night. The boss wouldn't have been crazy enough to try anything like that."

"Carry on as before?" Oxana suggests. "It doesn't need to make any difference."

"There wasn't any kind of boat or inflatable craft he could have taken?" I suggest helpfully, and Ginge shakes his head.

Ginge looks from face to face. "Everyone OK with that? We carry on as we were? Meanwhile I'll see what I can do about the lock on that front office. Pretty sure there's a satphone in there and that the antenna works."

"Our employers. Give them a heads-up about the boss."

"Got to be done, boyo."

"Rather you than me."

"Who you gonna call?" Nobby asks. "Ghostbusters?"

We return to the firing points. The sea and the sky are calmer today, and visibility much improved. Charlie's nailing pretty much every target at seven hundred meters plus, now. One shot, one kill, as Ginge continually impresses on us. From what I can see, Oxana's hit rate is every bit as consistent.

We spend our last night on the platform in my cabin. I tell Oxana about the encounter with Tikhomirov, and how he asked me to contact him if I discover what the Twelve are planning, and I say that, if possible, I intend to do exactly this. The more important our target is, I argue, the less likely it is that the Twelve will let us walk away when the job's done. We're more than expendable, we're a liability.

If I can make contact with Tikhomirov, on the other hand, and provide him with enough information to intercept us before we fire a shot, he may see an advantage in keeping us alive, and letting it be known that we were acting as his agents all along. Oxana is briefly angry that I didn't tell her earlier and deeply suspicious of any alliance with the FSB, but agrees that in the long run we are probably marginally better off relying on the state security service than the Twelve.

"Exactly. To try to get a message to him."

I tell her my plan, such as it is, and she considers it in silence.

"That's not what it's about, though, is it? I mean, you're not really interested in making the world a better place."

"Mmm… no. Maybe not."

"Easy for you to say, with a body like a weasel on steroids. But go on. Remind me. What is it about murder that turns you on so much?"

"I'm good at it. Every ocean needs its sharks. Every kill I've carried out has left the world a better place."

"And you're not a sadist. You don't get turned on watching people suffer."

"I wish you didn't enjoy it so much."

"Could work," she says eventually, stroking my cheek with cold-roughened fingers. "At the same time I'd kind of like to go through with the hit. I'd love to pull the trigger on someone really high profile. Just to sign off."

"Not particularly." She slides her hand down my back. "Apart from you, obviously."

"I love your bum."

"And this is what you wanted the pencil for?" she asks me.

"Very funny. And stop wobbling my bum."

"Meaning not to be that bitch, sweetie, but you're a murderer too. Twice over."

"I could ask you the same question."

"What, eat a whole box of marrons glacés at one go?"

"Hack into my email and masturbate?"

"And I did? You really think I could say no, sorry, Konstantin, I can't carry out your contract. I've got a hairdressing appointment at Carita in the morning, then lunch at Arpège, and in the afternoon I was planning to hack into Eve Polastri's email, masturbate, and eat a box of Fauchon marrons glacés."

"You know perfectly well. I had no choice."

"You did that?"

"Were?"

"Well, yeah, OK, but both of those were…"

"Why would I take nude selfies?"

"Meaning?"

"Current?"

"I tried. But it wasn't interesting. No sexy messages. No nude selfies."

"For me to find, obviously. I wasn't going to finger myself over your bank statements. But back to you, pupsik. You're so many things. You're an ex-spy, although if we're being honest not a great one. You're Niko the asshole's ex-wife. You're my current lover."

"Yes. Means right now."

"I know what it means. I speak English. It's just a bit… Couldn't you just say you're my lover?"

She nips my cheek with her teeth. "I'm teasing you. But yeah. You're clever, a bit nerdy, and quite needy. You're a scaredy-cat but also weirdly brave. You're sexy and adorable in bed and you're a really, really terrible cook."

"Thanks."

"How do you know?"

"I've seen inside your fridge. It was tragic."

"Yes, you have zero fashion sense."

"Anything else?"

"The point I'm making is this. That if I took all these things away from you, if I peeled it all away, layer by layer, there'd still be you. Underneath everything, there's Eve. And you know that about yourself, you know exactly who you are. But I don't have that. If I take away everything I've done, and all the people I've been, or pretended to be -- all the layers -- there's nothing. No Villanelle, no Oxana, no self at all, just a…" She's silent for a moment. "Did you see that film, The Invisible Man? You couldn't see him, but you could see the effect he had on the things and the people around him. That's how I feel. The only reason I know that there's a me, an Oxana, is that I see the trail she leaves. I see the fear and the horror in people's eyes, and that tells me that she exists -- that I exist. Konstantin understood this perfectly. He knew that I needed to make the world echo with my presence."

She shrugs. "If it's some real high-end evil motherfucker I wouldn't want the job to go to anyone else."

"But my loving you is obviously not enough, since you still want one last kill."

"You, pupsik. You do. You look at me with such tenderness, and such love. For the first time since I was a child, since that visit to the Kungur ice caves, I feel seen. I feel that there's someone there, underneath all the bullshit. A real Oxana. A real me."

"It made me feel alive. Those kills that I carried out for Konstantin were beautiful. Perfectly planned, perfectly executed. Fucking works of art, to be honest."

"I'll walk away, trust me."

"What else does?"

"Maybe I do."

"And this made you feel powerful?"

"Because killing for the Twelve is not the only thing that makes me feel alive. Not anymore."

"Why would you?"

"And you want one more hit of that drug before you walk away? One more smack rush? One last high?"

"But can't you see? If that's what it takes to make you feel alive, you'll never walk away. There'll be one more kill, and then one more, and one more after that. Until someone kills you."

"Do you think Nobby and Ginge know the target?"

"No, pupsik, we don't. So stop talking and come here."

"Supposing it's someone not evil at all? Supposing it's a woman?"

"Because I know how the Twelve work. Everything's arranged so you're not left hanging around. You're given time to prepare, but not too much time, because the longer you keep people waiting, the more likely it is that there'll be some kind of security issue. My guess is that it'll be within a couple of days of our leaving here."

"I didn't say I wouldn't, I just said I hadn't."

"I've never killed a woman."

"Why do you say that?"

"That's very sisterly of you."

"Truth is, we don't have any choice about any of this. When the time comes they're going to deliver us to our firing points, and we're just going to have to do it or get killed. If I try to get a word to Tikhomirov, at least we've got a chance."

"What would you tell him? We don't know anything useful. No who, no where, no when, no why."

"It'll be very soon."

"We don't have much time then."

"You're right, we don't. All we know is the range. And that's not much help."

"They don't need to, so no, I don't. They're just old army mates of Anton's. And I doubt he knew, either."