The place I think of as my secret underground restaurant in Istanbul is actually pretty well known – Michelin rated, in fact. It is situated in the vaults of an old Ottoman building, with staff who look like they might also DJ serving natural wines. And if it is, in places, subterranean, this restaurant, like the topsy-turvy streetscapes of the Escher-esque city, is, elsewhere, somewhere high above. Istanbul, a joint between two continents, a bridge between East and West, was the espionage capital of the world for the first half of the 20th century.

On this night, a blazing peach-coloured full moon pops up suddenly, down keyhole alleyways and through pointed archways. It lights my way on a rambling return to the touristy neighbourhood of Galeta, back to a favourite little textile shop in search of a silk robe. But the store is closed and my soaring ambition for a cloak-and-dagger prop for the journey I’m about to take aboard the Venice Simplon-Orient-Express to Paris is in vain. So I do what I think of as a Jungian reward and let my other self, my shadow self, order whatever he wants in this underground restaurant, as a treat, feasting on cured sea bass and Jerusalem artichokes, chicken confit and kepse pilaf.

When we disembark in Bucharest, the click of a leather heel on the marble floor of our hotel reminds me of something in Lawrence Durrell’s The Alexandria Quartet. Something about elegance, maybe, and exoticism, a diplomat walking alone through a cool embassy of an afternoon. Outside, a wedding party is pouring out of Bentleys the size of tanks to walk through a gauntlet of trays carrying flutes of champagne. We retreat to our rooms to dress in suits and skirts for a visit to a famous old beer hall for dinner, dancing and singing.

I’m curious about that strange sense of memory, the click that made me crave a specific feeling. Is it glamour? Elegance? Glamour seems like it must be disembodied, like a kind of shine, a shimmer, filament-fragile – the warm light behind all of the glitz in the world. Elegance, on the other hand, is articulated in things, in behaviour. The taper on a cigarette holder. The splintered reflection off cut crystal. That night I return to the spy novels I’m reading, for the feeling of wanting to walk on marble, what it is like to wear a Savile Row suit and meet a contact at a masquerade ball.

As the train moves through a dense emerald forest in the Carpathian Mountains, we stop at a station in Sinaia to visit the former summer palace of Romania’s first king, Carol I. A rain shower has just cleared but a blue mist hangs low so that at times our heads are very nearly in the clouds. So too was Carol’s when he constructed this palace. One chamber is a tented Ottoman-style sitting room, the next a Moroccan tea parlour and further on is a Byzantine library complete with secret passageways.

In the arsenal, packed full of swords and knightly suits of armour, I wonder if Carol had taken the acquisitive search for souvenirs to its fetishistic end. Here he made a one-man Disneyland with the talismans of his various fantasy selves, all of the possible and potential iterations of himself. And it gives me some comfort that we are all merely aspiring Carols or Disneys, wanting to build an imaginary world into the real one, to make and manifest the places to which we can escape. Mostly, though, being short of a king’s budget, only in our minds.

The train pulls into Budapest and I set out on my own — revisiting, revising, recreating experiences from a previous trip like some sort of travelling tic — to wander the settings of my favourite spy movies, many of which were filmed here. In the Párizsi Udvar arcade, I drink where Jim Prideaux had his fateful pastry in Tinker Tailor Soldier Spy; at the Hotel Astoria, I photograph the hallowed spot where Robert Redford and Brad Pitt filmed the climactic rooftop scene in Spy Game – a bit of a camp pilgrimage.

I am worlds away from reality when I wander into an actual war scene back at my hotel. It takes me too long to realise that I have, in fact, only walked onto a set – sandbags, bunkers, army cars, and men and women in period costume – before I reverse direction and clamber up to the hotel bar for a martini, and then a second. The author of one of my spy books calls the act of espionage “enchanting the mundane”. In another, when two contacts are parting ways and custom forbids them, like actors on a stage, to wish one another good luck, they simply pick a city they love and promise to meet again there. “See you in Istanbul,” they say. Like throwing a coin into a fountain. The promise of a return. “Istanbul, then.”

This is an abridged version of this article. To read in full, pick up a copy of Mondes magazine during your next stay with Belmond.

BOARD THE VENICE SIMPLON-ORIENT-EXPRESS