What, I wonder, would Bond have thought of the train claimed to "set new standards for overnight rail travel in Europe"?
As we gather speed on our two-day journey down the "glittering tracks", in Fleming's words, I feel sure of one thing. He would have liked the beds.
Since Fleming's era, a lot of nonsense has been talked about the so-called "romance" of night trains. The reality usually involves cramped compartments, hard "beds" converted from daytime seats, and primitive washing facilities.
Even the most famous trains are not exempt. The Venice Simplon-Orient-Express - promoted as one of the world's most luxurious trains - is something of a passion killer.
No proper beds, no en suite lavatory facilities or showers and, to the horror of many American tourists, no air-conditioning.
The passengers embarking on the maiden voyage of the Danube Express encountered something rather different last week.
There were real beds with proper mattresses in double berths, en suite showers and toilets, air-conditioning and soft lighting, with just five spacious sleeping compartments in each car.
Previously, they served as the travelling post-offices of MAV, the Hungarian State Railways.
The mail train bogies now have a different purpose - to soothe the customers to sleep in their comfy beds. And the smooth ride will do nothing to hamper the libidos of those determined on Bondish pursuits.
As it turns out, my journey is to be more Smersh than Bond, as the steward leads me through swaying gangways to the front of the train. Here the coaches are older, the curtains thicker, the blinds more impenetrable, and the mahogany more burnished. And the sense of mystery thickens.
These historic coaches are marshalled into the train from Hungary's national collection of vintage rail vehicles. Eventually we arrive in car 54, where the door slides open to reveal a spacious compartment, complete with one of the widest train beds I have seen. No wonder it's known as the VIP suite.
In its former incarnation it was the personal quarters in the private coach of the last Communist president of Hungary. Members of the Hungarian ruling elite were not known for skimping on the luxuries they denied to the proletariat, and President Janos Kadar was no exception.
So I settle back for the journey, amid authentic 1950s "commie chic" - plenty of Formica, Dralon, tasselled curtains, Art Deco lighting and a beaten-copper table where the president liked to play chess.
Instead of the gun-toting guards who would once have been stationed outside the door, stewards (one is inappropriately named Atila) wait patiently on my every need. Can I smell a steam engine at the front of the train? No, it is just the stewards stoking up the coal-fired stove along the carriage that heats up my personal radiator and hot water.
It is this rather gentler nostalgia that defines the Danube Express's journey south along the banks of the Elbe and the Danube - as we pass through a timeless world of Middle Europe, still dominated by the ghosts of Slavs, Magyars, Tatars, Ottomans and Habsburgs.
The tone is set by the names of the new coaches, taken from the ancient Roman provinces through which we pass: Pannonia, Vindobona and Kracovia.
First stop is Dresden, melancholy in the rain, with many of the architectural splendours reconstructed after the devastation left by Allied bombers in 1945 and the concrete horrors of Soviet-era rebuilding.
In the square by the Frauenkirche, ostnostalgie is very much alive, as stallholders do a roaring trade in model Trabants (the one I buy is metal, a great improvement on the real thing).
Back on the train, there is more nostalgia as the whiff of a roasting goose for supper fills the carriages. In a world where train meals are now rarely created outside a microwave, there are few better sounds than a sizzling oven as we pass through the restaurant car to take our seats.
And over the next two days, the chef recreates some great Hungarian classics - Hortobagy pancake, chicken and mushroom ragout, and pungent red cabbage, apple and sour cherry strudel.
Rocked to sleep by the old-fashioned clicketty-clack of the rails, we awake amid the Tatra Mountains in Slovakia, which is surely the modern incarnation of Ruritania, where the official rail map shows the hills still to be inhabited by wolves and bears.
We stop for a break in the second city of Kosice, where I had to pay in koruna (euros become legal tender only in the New Year) for an over-large pair of Eastern European swimming trunks. Locals still drink in a bar dressed up with Lenin memorabilia.
Journey's end is Budapest's Nyugati station, with its elegant wrought-iron roof built by Gustav Eiffel - and a glass of champagne in the dusty, baroque surroundings of Emperor Josef II's personal waiting-room, opened especially for the train's arrival.
Next spring, the Danube Express extends its iron horizons to other great capitals of Eastern Europe and beyond - Prague, Vienna, Sofia and Istanbul.
So what would Bond have made of it? More homely than exotic, I suspect. I did not fall into the arms of Tatiana or anyone like her. Nor did I manage to solve the mystery of the Spektor encryption machine.
Maybe this was no bad thing, since there were other compensations.
It was famously said in Hungary that, like Stalin, its Communist leaders "never slept".
I am happy to declare that, coddled by the train in the president's bed, I had one of the best night's sleep of my life.
- INDEPENDENT