The helicopter comes for us at midday. Aboard are two Twelve paramilitaries, both carrying sidearms. They jump down onto the platform, carry out a thorough search of the entire installation, nod cursorily at Nobby and Ginge, and shepherd us on board the Super Puma. As we swing away into the wind I peer downwards, suddenly fearful that Anton's body will appear, arms outstretched, borne up by the choppy waves. But there's nothing, no accusing corpse, only the diminishing figures of Nobby and Ginge on the platform, and the gray wastes of the sea.

When faced by danger, Oxana and I are polar opposites. I foresee terrible outcomes, and become possessed by fear, while Oxana's sense of impending threat is so shallow as to barely register. As her body prepares itself for action, her mind remains calm. It must be the same for Charlie, who lounges back in their seat, chewing gum that they've somehow extracted from the soldiers, and studiously ignores us.

At Ostend, the two men keep us on a short rein, fast-tracking us through security and passport control and marching us out onto the tarmac, where the Learjet is fueled up and waiting. I squeeze Oxana's hand as we take off, and keep hold of it. Our destination, as expected, is Moscow. The engine noise is little more than a discreet hum, but I'm too nervous to talk.

"Nothing. I'm just saying. Whichever way this thing plays out."

"Glad you left England with me?"

I touch her cheek. "Did I have a choice?"

I nod. There's so much to say, and I can't say any of it.

"Are you all right?" Oxana asks.

"I know what's best for you, pchelka. Just trust me, OK. I know there was the Charlie thing, but seriously. Trust me."

"I'm worried now. What do you know that I don't?"

"I'm so scared."

"Shit, sweetie. Talk to me."

"I don't know anything, I'm just saying. Trust me. Trust us."

Scared or not, I proceed with my plan. After breakfast on the platform I surreptitiously tore a small blank strip from a page of Birds of the North Sea and glued it into the back of my passport, using a couple of dabs of honey. Now, as soon as we're airborne, I take out my hard-won pencil and write, heading the message with the telephone number that I've memorized, and asking the person reading it to call the number urgently, on a matter of state security, and deliver the following message to General Tikhomirov: 2 shooters, this week, range 700m.

"I know, babe."

Entering the airport buildings, we're fast-tracked through a small VIP customs hall. There are two officers, dressed in bulky green winter uniforms. An older woman with tiny, granite eyes, and a shaven-headed young man whose broad-brimmed cap is several sizes too large for him.

Shortly before we begin our descent to Moscow, one of the paramilitaries collects our passports, securing them with an elastic band. We seem to circle the city forever, and as we go through landing and disembarkation procedures at Sheremetyevo I'm so terrified I almost vomit. If the paramilitary examines the passports, as he well may, that'll be the end. If I'm lucky, it'll be a bullet in the back of the head. I don't want to think of the alternatives.

Our paramilitary chaperone takes our passports from his pocket, removes the elastic band, and as he flicks through the pages of the top passport before passing it to the woman, I feel my knees begin to shake. I'm guessing that my face has gone white, because Oxana puts an arm round me and asks if I'm all right. I nod, and the other Twelve guy peers at me suspiciously. "Delayed reaction," I stammer. "Flying. I get very nervous."

"Give them all to me," the granite-eyed woman orders. Her name tag identifies her as Lapotnikova, Inna. Taking the passports, she opens the first, looks up, and beckons Charlie to the counter. I'm second in line after Charlie. I watch Ms. Lapotnikova slowly page through the forgery, and come to a halt as she reaches the page with the note. She reads it expressionlessly, and slowly looks up at me, one eyebrow raised questioningly. I nod imperceptibly and she discreetly pulls out the note and returns my passport to me. Then handing the remaining three passports to her colleague, she unhurriedly leaves the room.

For a moment I'm weak with relief, then it occurs to me that she may simply have gone to call airport security. Perhaps she thinks I'm some deranged conspiracy theorist. Either way, I'm finished. Under my suddenly too-hot clothes I feel a sweat bead running down my spine. I try to look casual and Oxana squeezes my hand. "Relax," she murmurs. "You look like you're trying not to shit."

Lapotnikova returns just as the customs officer in the big hat is handing back the last of the passports. She ignores me and returns to her seat. I want to hug her. We're through. I've done everything I can, the rest is up to Tikhomirov, although whether my message will be the slightest help to him, I don't know. I'm guessing not.

As we approach central Moscow, we're forced to negotiate street barriers, road closures and diversions. "What's going on?" I ask the driver, as the traffic slows to a standstill.

"New Year's Eve celebrations," he answers, irritably negotiating a three-point turn.

"Do you know the expression 'muffin top'?" she whispers.

We're driven back to Moscow in the same SUV, this time by one of our armed guards. The second guy sits in the passenger seat with his pistol in his lap, presumably in case one of us tries to filch it from its holster. I'm in the back seat, as usual, between Oxana and Charlie. The symbolism of this arrangement is not lost on Charlie, who stares pointedly out of the window for the entire journey. Oxana, kittenish at the prospect of action, creeps her fingers under my sweater and round my waist, tickling and pinching me.

"No. Day after tomorrow."

"Not tonight, surely?" I've lost all track of the date.

We're delivered back to the twelfth floor of the gray skyscraper and shown to our old rooms. I'm scared, in a generalized sort of way, but mostly I'm just very, very hungry. Whatever tomorrow holds, there's tonight's dinner to look forward to, followed by a night in a full-sized bed with Oxana. For now, that's enough.

"You knew him better than anyone else, Villanelle. How did he strike you?"

Below us, as dusk falls, Moscow lights up. The New Year decorations are in place, and the streets, cathedrals and skyscrapers are a blaze of gold and silver and sapphire. Gazing out of the window, I think how wonderful it would be to be able to explore the city with Oxana, unburdened with fear and horror and dreams of death, and lose ourselves in the dazzle and enchantment of it all.

At dinner, Richard questions us closely about Anton. Charlie does most of the talking, explaining that the general consensus was that he'd been drinking late at night, and had fallen off the platform.

"He was like he always was. I never liked him that much but he was professional, and ran things properly. Everything was well organized, supplies, weaponry, all that. And then one morning he just wasn't there."

"Eve?"

"What can I say? I couldn't stand the man, but like Oxana says everything ran smoothly. I just kept out of his way."

"Lara?"

"My name's Charlie. And yeah. What the others said. But I'm pretty sure he was drinking. I was making myself coffee one morning before breakfast, and he came in smelling of alcohol, like it was coming out of his skin. Obviously I didn't say anything to him, but --"

"They didn't ask me. And after he disappeared I didn't want to say negative things about him in case people blamed me. But it's true."

"What, again?" Oxana says.

Richard brightens. "Who'd like some wine? It's the Château Pétrus."

He smiles. "We must celebrate your return. Seasonal greetings, and all that. I believe our little North Sea getaway is quite chilly at this time of year." He fills our glasses. "Good luck to you, ladies."

The next day passes with stifling slowness. We're not permitted to leave the twelfth floor, or to do anything except pace around like zoo animals, breathing the building's recycled air. There are no books, no newspapers, no computers or phones. Oxana and I have temporarily run out of things to say to each other, and I spend most of the afternoon sleeping. After dinner Richard announces a film show, and we follow him into a projection room with a screen covering most of one wall. "It's not long, and there's no sound," he tells us, as we take our places. "But it's quite an eye-opener."

I glance at Charlie. They're looking at me, not with hatred or jealousy, but levelly, as if to say that now we're square, and I give them the ghost of a nod.

"Did you tell either of the instructors?"

"And to me," says Charlie.

"Absolutely not."

Stechkin and Loy stand, place their empty tumblers on the mantelpiece, and shake hands. Loy then walks Stechkin to the door. The film cuts and then reprises from the same viewpoint with lower lighting as the door opens and three young women walk in. They're all blond, long-legged, and spectacular in a listless, stoned sort of way. Loy leans back in his chair, nods, and issues an order. The women undress, drape their clothes over the vacant armchair, and start kissing and caressing each other's breasts with much eye-rolling and simulated groaning.

There are no titles, just a recording date and a time code. Then a silent, wide-angle shot of a hotel suite from a fixed camera, almost certainly concealed. The quality of the film isn't great, but this is clearly a very upscale, thousands-of-dollars-a-night sort of place. The color scheme is parchment and oak, the curtains are ivory silk, the lighting is discreet. Two men in suits, holding whisky tumblers, sit in armchairs on either side of a marble fireplace. Both are immediately recognizable. One is Valery Stechkin, the president of Russia, the other is Ronald Loy, president of the United States. Both have the rouged, powdered look of the recently embalmed. A third man, with the watchful demeanor of a bodyguard, stands by a door.

"Not lookalikes?" I ask Richard.

"It's all in her hair," says Charlie. "Yuck."

Eventually we're treated to the full three-way performance. It's pretty dispiriting. Loy doesn't join in, but sits back in his chair, his expression disdainful. When one of the women experimentally waggles a glistening strap-on in front of his nose, he responds irritably, batting it away with a tiny, childlike hand.

"Get on with it," Oxana mutters.

The film cuts to a bedroom furnished in the same rich, fustian colors. The bed itself is enormous and covered in gold damask. The three women walk into the shot, followed by Loy. He orders them to climb onto the bed, where they bounce up and down in a desultory fashion before coming to a halt, crouching down, and as one, beginning to urinate onto the gold coverlet.

From his chair, Loy stares at the women through narrowed eyes, as if watching them was a wearisome but essential presidential duty. Halfway through the process, one of the women overbalances on her high heels and tips forward, sliding off the bed in a torrent of piss.

"They're really nice. Or they were."

"And those suede boots are ruined," adds Oxana.

"They're Prada. In Paris, I had two pairs. One in camel and one in anthracite."

Finally, blessedly, the scene comes to a close.

"That girl on the left's been peeing for almost a minute," Charlie says. "She should go on Russia's Got Talent."

"Oh boo," Oxana protests. "I was really enjoying that."

The lights come up in the room, and Richard looks at us one by one. "Villanelle, I'm happy that you liked the show but it wasn't intended as light entertainment. That short clip has had a greater impact on world history than any political event, debate or policy decision in the last decade. Holding this trump card, this kompromat, has enabled Stechkin to steer the White House as he chooses. Not just to steer it but to throw it into a catastrophic reverse. Meanwhile the Russian Federation over which he presides like a latter-day Roman emperor is sclerotic and corrupt to the core.

"I'm telling you this because I want you to believe in what we, here, are trying to achieve. The new world we dream of will not be brought about by democratic process, that dream is dead. It'll be brought about by decisive action, and you three are going to be the prime movers of that action. Your targets are Ronald Loy and Valery Stechkin, the presidents of the United States and Russia. They die tomorrow."

"I just wish there was some way out."

"Everything's checked and ready. You don't have to worry. You'll be taken to your locations, where you'll find everything you need, and last-minute details will be dealt with in situ. So get a good night's sleep."

"The girls in the film."

"No, of course not."

Unsurprisingly, I can't do any such thing. I lie with my back to Oxana, who has her arm around me and her face in my hair, trying to find a gleam of hope in what lies ahead.

"So when do we get a proper briefing?" Oxana asks. "Tomorrow's cutting it very fine. We need to recce the firing points, prepare the weapons, all that."

"And the girls?" Charlie asks.

"Mmm. Also true that the only way they were going to get me -- the best -- was to take you too."

"We don't have to kill them?"

"What about them?"

"What girls?"

"I know why I was chosen to be part of this," I tell her. "It's so that if everything goes wrong, they can point at me and say that the whole thing was cooked up by MI6. I'm their alibi."

"Phew."

"There isn't, pupsik. But it's not as if you're going to be pulling the trigger."

"I know that. I just want us to end up together. Not dead or imprisoned for life."

"We're not dead yet."

"I love you too. Now go to sleep."

"Not yet."

Her arm tightens and she presses herself against me. "Trust me, pchelka."

"I do. I love you."

In the morning she's not there when I wake, and nor are her clothes. I pace the corridor, and look in all the rooms that aren't locked, but she's gone, and I feel wretched. At breakfast, there's just Charlie and me. We sit in silence. They wolf down a full cooked breakfast. I manage a bread roll with gooseberry jam and coffee.

"We should get our cold-weather gear ready," Charlie says. "Thermals, gloves, hats, all that stuff. We might have to lie up for hours at the firing point."

Afterward, no one comes for us, although there are the usual anonymous figures going in and out of the offices. So we sit in the restaurant area, staring out of the windows. It hasn't snowed since we arrived back in Moscow, and the sky is a cold, hard blue. On the building's exterior, icicles hang from the window ledges.

"I knew him a lot better than you did, and he wasn't a drinker. He hated the idea of losing control."

Afterward they fold their arms and look at me. "You killed Anton, didn't you?"

I shake my head. "Sorry, but that's crazy. I mean seriously, why would I kill him? And more to the point, how?"

"I don't know how. But I'll tell you what's crazy. That story of him drinking half a bottle of brandy and falling off the edge of the platform? There's no way he'd let that happen."

"Look, I don't know what happened to him, OK? End of story."

Charlie smiles. "I'm not going to say anything, Eve. But I just wanted you to know that I know. OK?"

They're right. I assemble the warmest clothes I've been issued, and leave everything else in my room. I'm under no illusion that I'm ever going to see it again. Hours pass, lunch comes and goes. I feel a nauseated apprehension, but Charlie's appetite is unflagging.

"What the fuck, Charlie?"

"Whatever, Charlie."