As my details were inspected and my tickets stamped, I flicked through the file marked Kepler.

Nearly a hundred photos and names, faces, glimpses of old CCTV pictures, arrest warrants, family photos. Records of interviews and documents logged, emails sent and phones hacked. Some of the faces in the file I barely remembered; others had been part of me for years at a time. There the beggar I had met in Chicago whose face, when shaved, turned out to be barely a boy’s, and whose body I enrolled, as my very last act in it, on a catering course in St Louis, reasoning there were worse places to begin again. Here the woman from St Petersburg whose companions had loved her and left her, and who I’d found wandering the streets without the money to get home, and who hissed, “Vengeance against all false friends…” There the district attorney in New Orleans who, sitting beside me in the bar, had said, “If he testifies, I can blow this case wide open, but he’s too goddamn scared to come to court.” And I’d replied, “What if I could get him there?”

Here, over ten years of my life, laid out in neat chronological order, every jump, every switch, every skin, tracked and documented and filed for future reference, right up to the very last page, and Josephine.

Someone had spent years tracing me, monitoring my every move through records of amnesia, the testimonies of men and women who had lost an hour here, a day there, a few months at a time. It was a masterpiece of investigation, a triumph of forensic detection, right up to the point where, without explanation, it took it upon itself to lie shamelessly and brand both me and my host murderers.

I pulled a few pictures from the file.

A woman, sitting in the window of a café in Vienna, her cake untouched, her coffee growing cold.

A man in a hospital gown, a tawny beard spreading across his round sagging belly, staring out of the window at nothing much in particular.

A teenage boy, his hair stuck up in ozone-destroying spikes, giving two fingers to the camera as he waggled his pink pierced tongue. Definitely not my type but perhaps, given the circumstances, his presence in my file was fortuitous after all.

Chapter 16

As the train slowed into Belgrade, I checked my belongings.

Passports, money, weapons, mobile phone.

I put the battery back in the phone and thumbed it on.

It took a while to work out its location and then grudgingly conceded that yes, it was in Serbia, and sent me a text message to inform me of the same and ask me to enjoy my stay. I waited. Two new messages. The first was a missed call, no message, number unknown. The second was a text message. It read: SOS Circe.

Nothing more.

I thought about it a moment, then turned the phone back off, removed the battery and put them away at the bottom of the bag.

What may be said of Belgrade?

It is a bad city in which to be old or cantankerous.

It is a fantastic place to party.

The station is a monument to triumphant 1800s ambition, a palace of fine lines and handsome stones that put Kapikule to shame. Step outside and taxis honk, cars scrunch head to tail, trams and trolley carts compete for space beneath the spider’s web of overhead power lines feeding the transport system, and a couple of tower blocks stand still, grey and empty where once–not so long ago–NATO cruise missiles fell. A proper heart-of-city station, the smell of the rivers pushes back against exhaust and cigarette smoke as the Sava and the Danube collide, determined to prove that whatever meagre definition of ‘river’ you’ve been working on up to now, you ain’t seen nothing yet. It is easy to believe, when you stand on the shores of the Danube, that the world is an island after all.

By night the barges that hug the waterfront turn up the music and the disco lights, and the young come out to party. By day the pedestrianised streets of central Belgrade are swamped with the fashionable come to buy fashionable things, to sustain their sense of fashionability, while on the edge of the city the old folk sit, men with drooping cigarettes and time-sunken eyes, who stare at the swaggering world and are not impressed.

Cross the waters of the Sava, and long shadows are thrown by the tower blocks and industrial slabs of communist dreams with such catchy names as Blok 34, Blok 8, Blok whatever. It is a place perhaps more real than the dream of exclusive boutiques that line Prince Mihailo, where life is not glamorous, and fashion serves no purpose apart from provoking envy and contempt.

I checked in at a hotel that was one of a thousand hotels run by ten companies the world over. I used the German passport and the woman exclaimed in poorly accented Deutsch, “Ah! Welcome you here very much!”

My room, unlike in Edirne, had the space, uniformity and whitewashed luxury expected by any bug-eyed European traveller who is now too tired to want to think about where the kettle is or watch anything other than CNN sports reports or repeats of CSI. I locked my case away, put a few hundred euros in my pocket, tucked the Kepler folder under my arm and went in search of an internet café.

On page 14 of the Kepler file there was a photo of a man.

His hair was dyed black, his nose, chin, ears, jaw burst with pieces of metal, he wore a T-shirt with a white skull on it and, if it hadn’t been for the prescription-strength glasses on his nose and the textbook on Prüfungs Gemacht Physik in the background, I would happily have dismissed him then and there as your average happy punk.

The note in the file read: “Berlin, 2007. Johannes Schwarb. Short-term inhabitation, long-term association?”

Looking at the leering expression on the studded face, I shuddered to think that I had ever even considered habitation of that flesh, brief though it had been.

Chapter 17

He was sixteen, I was twenty-seven, and he was hitting on me in a Berlin nightclub.

“No,” I said.

“Come on…”

“No.”

“Come on, babe…”

“Absolutely not.”

“Come on…”

The bar was loud, the music was good, I was Christina and had a taste for mojitos, he was Johannes Schwarb and he was high.

He waggled his tongue at me like a flailing fish, revealing the stud protruding from its flapping pink surface. “Young man,” I said, “you are all of thirty seconds away from self-harm.”

My statement, true as it was, didn’t seem to be comprehended by Johannes, who kept on writhing whichever parts of his body he still had some sort of control over up and down against the stool by my side. He hadn’t mustered the courage to writhe against anything living, so the furniture would have to do. For a brief moment I contemplated doing the unthinkable, grabbing his face and putting my tongue down his throat, just to see what happened.

Odds were, he’d be so shocked he’d bite, and it seemed unfair to leave Christina with a swollen tongue and the taste of vodka.

Then his friend ran up, and she was fifteen, and she was crying, and she pulled at his arm and said, “They’re here!”

“Babe!” he wailed. “Can’t you see I’m…?” A gesture attempted to take in the curves of my body, the shape of my dress, the look of murder in my eyes.

“They’re here,” she hissed. “They want the money.”

Her eyes darted across the dance floor, and his followed, red capillaries wiggling through the whites, body half-falling as he twisted to see the source of the disruption.

Three men with the faces of those for whom a party was a source of profit, no more, were heading across the floor with the determination of a Roman road. Johannes whooped, stuck both his arms in the air, revealing a well-pierced midriff, and shrilled, “Hey! Motherfuckers! Come get it!”