André was shocked and annoyed to be caught out by his little sister, but he didn’t deny it. In the end, after I applied thumbscrews, he admitted he worked undercover for the CIA – the American Central Intelligence Agency – to help save France from falling under Communist domination.

‘France is sleep-walking right into the Soviet Union’s open arms,’ he warned me. ‘Our country needs to wake up. Vite. And the only ones who have the firepower to protect the whole of Europe from the Communist threat are the Americans.’

What I’d seen him do on the street that day was pass information on a new Soviet sleeper about whom he had suspicions to another CIA agent. When I asked the obvious – ‘Why don’t you just hand it to him over a drink at Maxime’s?’ – he’d just laughed and told me I had a lot to learn.

‘So teach me,’ I’d said.

That’s when I learned to pick locks, work a daylight and night-time trace on foot and on wheels, to decipher different kinds of codes and to use a spy camera. By the time I left the Sorbonne, I was a cherry waiting to be picked.

*

After leaving André’s room, I went straight to mine and pulled my suitcase from under my bed. I opened it and from the bottom I dug out his wallet.

Why burn it?

I had scoured every inch of its black leather and discovered no hidden messages. What was it he wanted destroyed, what secret did it hold? I removed the banknotes – about one hundred thousand francs in various denominations. Since the war our money had gone crazy with the devaluation of the franc, so a hundred thousand francs sounds far more than it actually was – in real money it was a bit less than one hundred British pounds, or around three hundred American dollars.

That was still a lot to carry around. Don’t think I hadn’t already examined every one of the banknotes with a magnifying glass, because I had. Nothing. Just banknotes. Also in the case sat a roll of black felt, bound with tape. I removed it and unrolled it on the floor. Nestled within were my tools. I picked up the scalpel which lay beside the lock-pick, and sat down on the floor with the wallet. Neatly and carefully, the scalpel blade sliced open every stitch and prised apart the areas glued together. When it was all in pieces I examined the leather spread out in front of me and at first I saw nothing. I fingered the raw underside of the dark leather that I’d not seen before until my fingertip suddenly found the slightest of indentations. I peered closer. Something. What was it?

Then I spotted it. Numbers in black ink. Three of them. I fetched a torch.

511609

271314

901906

It was a code. This was a message from André to someone.

But to whom?