Like the famous detective, Gavin Bell travels the classic Orient Express route across Europe, at a fraction of the cost.
The border guards were impassive men wearing black jackets, guns and surly expressions. It was the middle of the night and a cold, rain-laden wind was whipping the train, halted at a former outpost of the Iron Curtain.
It was classic crime-thriller stuff: high wire fences, lights glowing dimly in a railway yard, the Bulgarian flag flying from a forbidding, communist-era building bristling with antennas.
It was an Orient Express moment but we weren't aboard the opulent icon that glides between Paris and Istanbul at a cost of about £5700 ($8400) a person. We were on the Bosfor Express from Bucharest, one of a series of trains that retrace the legendary Orient journey - at a fraction of the cost.
It was my wife's idea. Enthused by Agatha Christie's 1934 murder-mystery novel, she had long dreamt of hurtling eastward across Europe on night trains. Which is how we found ourselves at Paris's Gare de l'Est, gazing at the departure board for the Deutsche Bahn City Night Line to Munich.
The silver coaches gleamed in the lamplight and our compartment was welcoming. We were travelling first class, which meant we had sleeping cars to ourselves - no risk of sharing them with a grumpy Paul Theroux.
It was an early-evening departure and there was a restaurant car, with "Hercule Poirot" sitting at an adjacent table. A middle-aged man with a remarkable resemblance to the actor Albert Finney, he was thinly disguised, with gold-rimmed glasses and a green silk scarf knotted artistically above a dark jacket. We passed an agreeable hour speculating about who among our fellow diners might be plotting to do away with whom. Later, a few glasses of wine were enough to rock us to sleep as our iron horse rattled through the night, bound for Bavaria.
We scheduled the journey to allow full days between trains in Munich and Budapest. In the former, we headed for the Muellersches Volksbad, an art nouveau temple of relaxation, with saunas, steam baths and hot rooms. It was winter and we looked out at ducks waddling in snow before we boarded the midnight train to Budapest.
This was a Hungarian train and the spacious sleeping cars were spotless, with burgundy decor. This time, the beds were bigger and the usual clanking and clunking of the night barely registered in our cocoon of comfort.
Morning brought our first view of Hungary, which was disappointing - a sewage plant and a large sign pointing to a McDonald's. But the scenery improved, with fields and forests under a cover of snow, and farming communities of solid little houses with red roofs clustered like friendly and inviting toy towns.
The problem with travelling by train is that one keeps wanting to get off to explore unfamiliar landscapes.
In Budapest, there was time for a sightseeing bus trip, a stroll around the Buda Castle area and immersion in the thermal springs of the Gellert Baths before boarding the Ister Express to Bucharest. This was our most luxurious train yet. Our compartment was roomy, with en suite toilet and shower and snuggly quilts.
Hot food was being served in the wood-panelled dining saloon but we were the only customers; the cook, the guard and the ticket collector sat at a corner table playing backgammon.
A few fellow passengers appeared at breakfast, mostly men drinking beer, as we rolled through a winter wonderland in the Transylvanian highlands. This was one of my favourite places, a higgledy-piggledy landscape of rustic villages, haystacks, old wooden fences and inviting footpaths. Railway workers, huddled around fires in the snow, waved as we trundled by.
Another hour, another world. Having seen what Stalinist madman Nicolae Ceausescu did to eradicate any semblance of beauty in Bucharest, we didn't stop for long. Forty minutes between trains was deemed enough. The grimy apartment blocks came and went and we were on the Bosfor Express on the last leg of our journey.
There were no catering facilities on this train but we had stocked up on Hungarian bread, ham, cheese and wine, and our friendly Turkish guard, Nazmir, brewed tea and coffee on a camp stove in his compartment. So we settled down for lunch in our travelling bedroom and surveyed Bulgaria. It wasn't a cheery sight. We had left Romania's woods behind and crossed a broad, brown river on an iron bridge into an industrial morass of docks, cranes and chimney stacks that rose gloomily into low clouds.
It was 3am when we were brought to a halt on the Bulgarian-Turkish border. In contrast with the hard-faced Bulgarian officials, we were welcomed to Turkey by singing football fans celebrating a victory. They emerged noisily from a duty-free outlet on a station platform as a policeman issued our visas and sent us on our way.
Above us, a bright crescent moon hung in the night sky like an image of the Turkish flag bidding us welcome.
The next day, a freight train broke down on the line and we were bundled into buses for the last few miles to Istanbul.
My wife was disappointed but the amiable chaos of the Golden Horn and the rocket spires of the Blue Mosque soon wove their magic in the city of a thousand sensations.
And Poirot was at the railway station to greet us, beaming from a film poster beneath the vaulted ceilings and stained-glass windows of the Orient Express restaurant.
First-class sleeper accommodation on trains from Paris (Gare de l'Est) to Istanbul, via Munich, Budapest and Bucharest, costs from £589 a person, twin share. Second class costs from £487 a person, twin share. See bahn.com.de, oebb.at and raileurope.com.au.
- Guardian News and Media