I set some chips down on a green square, changed my mind and pushed them over to blue. I sat back as the last few gamblers placed their own bets and the croupier looked expectantly, impatiently around. He announced “No more bets” and spun the wheel. It whirled, glittering, forever if banally like a Ferris wheel from a funfair.

Through its whirring gilt spokes I saw the woman approaching the table. The ball inside the wheel clacked and rattled around the vertical spinning cage of spokes, battering off the blurred edges like a fly trapped in a bottle. The woman – girl? – moved with an easy, swinging step, almost like a dance. She was very tall and slim, dressed in flowing grey, and wore a small hat with an attached grey veil. I thought of Mrs Mulverhill immediately, though the woman was too tall and seemed to move differently. Not that that meant anything at all, of course. Veils were just about still common enough at the time for her not to look out of place wearing one, though she still attracted some looks.

It was spring here in the southern hemisphere of Calbefraques. Perhaps five years had passed since that night in Venice when my little pirate captain had tried to talk to me and had died for it. I had been asked – perhaps twice a year at first, later once a year or so – by my Concern superiors if any other attempt had been made to recruit me to whatever paranoid cause Mrs Mulverhill espoused. I had been able to answer honestly that no, neither she nor anybody else had tried to do so.

I had by now become a trusted agent of the Concern, spending a slim majority of my time in other worlds, doing whatever was asked of me. It was mostly the very banal stuff: the delivering of objects, the couriering of people (not that I was especially good at that), the pointed conversations, the leaving of pamphlets or computer files, the tiny, usually mundane interventions made in a hundred different lives.

I had since made only one other intervention as dramatically salvationary as the one with the young doctor in the street, when the building fell down; I was sent to one of the topmost floors of a tall building in a Manhattan, to buttonhole a young man who was about to step into a lift. He was a physicist and the world was a fairly laggard reality so engaging him in a conversation featuring an idea or two that he – and anybody else there, for that matter – had never heard of was not difficult. This stopped him from entering the lift, which promptly plunged twenty storeys and killed everyone aboard.

There were two other occasions when I was asked to take rather more violent action, once in a sword fight in a sort of unevenly early Victorian Greater Indonesian reality (leaping in to defend a great poet and hack off the limbs of a couple of his attackers) and once when I transitioned straight into the mind of a very brilliant, very handsome but very headstrong young chemist who had made powerful enemies in a Zimbabwean United Africa. I became him for just the few seconds required to turn, aim and fire his duelling pistol – blowing his much more experienced opponent’s brains out – before exiting again.

My handlers were most impressed. I got the impression that ever since the affair in the Venetian bar they had had me marked out as a natural thug. I did ask not to have to do too much of that kind of blood-sport stuff in future, but I was also quietly proud to have acquitted myself so well. Still, every now and again I was asked, and I obliged.

Meanwhile, I had been learning. I knew more about the history and organisation of the Concern now and had studied it the way it studied other worlds.

Mrs Mulverhill, I’d learned – through rumour rather than any official channel – was the latest of the very small number of Concern officers who had gone bad, mad or native over the centuries. She had somehow evaded the network of spotters and trackers and foreseers who were supposed to guard against this sort of thing and might even have had her own supply of septus, the transitioning drug, though this probably just indicated that she had access to a stockpile she’d somehow built up while still in the fold, as it were, rather than a way of making it from scratch.

She was regarded as a strange, remote, almost mythical figure, and – given her patent irrelevance and powerlessness – one to be pitied rather than reviled, though of course one was supposed to report immediately any contact with anybody who might be operating in a manner similar to that of l’Expédience but who was doing so outwith its control and oversight, and that would certainly cover her and her behaviour. I was, in any case, still not sure my little pirate captain really had been her.

The woman in grey in the Flesse casino came up to the table and stood watching the play. The ball clicked and clacked inside the slowing wheel and settled into its trap when the wheel finally swung to a stop. Gold. I comforted myself that my first instinct – putting the chips on green – had been no more prescient than my later change of mind favouring blue.

The game went on. She refused a seat when one came free. I tried to see her face but the grey veil hid it effectively. She turned and left ten minutes later, disappearing into the crowd.

I lost fairly steadily, then won moderately and finished a fraction down over the evening.

I tested the air in the outside bar, on the terrace under the trees by the side of the river, the town centre a buzz of music and traffic under the lights on the far side. It was warm enough under the hissing table heaters. I had met some people I knew and sat with them for a drink. The grey-veiled woman was standing by the stone wall a couple of tables away, looking out over the river.

At one point, I was fairly sure, she turned and looked at me as I talked with my friends. Then she turned slowly away again.

I excused myself and went up to her. “Excuse me,” I said.

She looked at me. She put the veil up over the front of the little hat. It was a pleasant, unremarkable face. “Sir?”

“Temudjin Oh,” I said. “Pleased to meet you.” I put out my hand. She took it in one grey-gloved hand.

“And I am pleased to meet you.”

I hesitated, waiting on a name, then said, “Would you care to join me and my friends?”

She looked over at our table. “Thank you.”

Much talk, all very congenial. She said her name was Joll and that she was a civilian, not part of the Concern, an architect making a submission to the local authorities in the town in a couple of days.

The evening drifted on, people drifted away.

Finally only we two were left. We had got on terribly well and shared a bottle of wine. I invited her to see the town from my house on the ridge and she accepted with a smile.

She stood on the terrace of the house, gazing at the lights. I put my hand on the smooth grey surface covering the small of her back and she turned to me, setting her drink down on the balustrade and removing her hat and veil entirely.

We repaired to bed, with the lights out at her request. We had fucked once and she was still holding me in her arms and inside her when she took me.

Suddenly, I was sitting at the corner of another gaming table in a different casino. She was in the next chair, just round the corner of the table from me so that we could talk easily. The game was under way; the wheel in this version was horizontal, sunk into the table’s surface. It was spun by what looked like the top of a giant golden tap. The only colours on the table appeared to be red and black, though the baize was green.

“Hmm,” I said. My companion was looking much more glamorous and more heavily made-up than she had been, though the face was not dissimilar. Better cheekbones, maybe. Her hair was blonde where she had been auburn. She wore a lot of jewellery. I appeared to be heavier than I was used to being. Nice black suit, though. I went to smooth my hair down and discovered I didn’t have any. There was a polished cigarette case lying by my ice-filled drinks glass, and an ashtray. That would account for the gurgling feeling in my chest when I breathed, and the slight but insistent craving for tobacco. I looked at myself in the reflective metal of the cigarette case. Not a prepossessing figure of a man. My languages were French, Arabic, English, German, Hindi, Portuguese and Latin. A smattering of Greek. “This is, ah, interesting,” I told her.