The Thalys fast train to Düsseldorf departed in less than two hours from the platform adjacent to the Eurostar arrivals. I’d double-checked the departures board and cooled my heels for a minute. When the video of the station CCTV was played and replayed, I’d be spotted, eventually, exactly where I wanted them to find me: scoping out another international train, but one I had no intention of boarding. If whoever was looking for me concluded Germany was my next stop, it would buy me time. And time, as always, was golden. Head down, I’d scuttled off and buried myself in a crowd of Dutch students making for the Métro. I’d descended with them. At the bottom of the stairs I’d peeled off and ducked into a photobooth. After putting five euros in the slot, I’d sat there impassively, waiting, counting my breaths, listening to the weekend bustle beyond the curtain.

A few minutes later I’d emerged again on to street level by the Buffalo Grill, opposite the main entrance, ditching my bundled-up coat into a litter bin. Walking back into the station by the taxi rank, I’d lifted an unguarded Yankees ball cap sitting on top of a careless American’s rucksack.

I’d considered stealing his phone, too, but unlocking it would have been impossible. I could have bought a burner, but I needed to stay as low profile as possible. Unregistered phones don’t stay active for long in France – and authenticating the SIM card would require identification. Showing Doctor Mann’s stolen passport wouldn’t just alert London – it would ring an alarm bell loud enough to be heard as far away as Washington and Moscow.

I hadn’t thrown the passport away with my coat, though. Doctor Mann’s ID wouldn’t get me through immigration again – but his identity might still come in handy. The steps I’d taken to get to Paris would be revealing themselves behind me, pace by pace, hour by hour. The most I could do was give anyone in pursuit the runaround while I made my own best guess at what to do next.