The Riviera train line had one other stop inside Monaco, but once the rails left the Principality, they were allowed to emerge above ground and become scenic, travelling at the coastline as far as Nice, then meandering in and out.

I did not notice much of the glorious view. My mind was working harder than the engine that pulled us.

Basil Zaharoff. A man in his late seventies, Greek-born, but Russian-named, due to his family’s period of Russian exile. He learned his early lessons in criminality with the Istanbul fire service, setting houses aflame that they might be saved and treasures “recovered”—for payment. A lifetime in crime, bigamous marriages to wealthy women, sales of disastrously inadequate military hardware to both sides of conflicts—conflicts he had helped to create—coupled with industrial sabotage, let him compile a truly stupefying fortune during the Great War. He made friends in high places, and took care to purchase respectability with huge donations to worthy causes. His deft manipulation of newspapers, banks, and elections helped ensure an Allied victory, leading to high honours in France, England, and Greece—though whether those were meant to reward his service, or to ensure his silence, was a matter of debate. He had recently married his long-time lover, one of the richest women in Spain, a woman who had used her position to further his business interests. And then he had bought himself a principality, for the comfort of his later years.

Those eyes of his, switching so instantly from deadly to congenial. I felt as if I’d just tip-toed through a nest of scorpions.

What was Zaharoff’s link to Niko Cassavetes? The richest man in Europe and a young homme à tout faire made for unlikely colleagues, and even less likely friends. Oh, I could well imagine that Zaharoff had his busy hands in the smuggling trade, but any direct tie between the two would be like a friendship between King Edward and an apprentice gardener.

Yet I’d have sworn that Zaharoff had reacted to the dead man’s name. That he not only knew who Niko was, but knew that his death could be a problem.

His uneasiness had lasted only a moment before his face had resumed its unconcerned, even faintly amused expression. Because he knew he was untouchable by the likes of me? Even Sherlock Holmes had not been able to put a stop to the man.

Or was it merely that he knew we would find no evidence against him? Zaharoff himself would never have stood in Mrs Hudson’s sitting room and pulled a trigger. If Niko was a threat, or even an inconvenience, Zaharoff would have sent someone to do it for him—someone like a large, scarred bodyguard. Feodor’s immediate impulse had been to tackle me as an intruder, but he no doubt knew how to use the gun he wore. A gun that, unfortunately, I hadn’t seen closely enough to see what size bullet it would fire.

And where did Mrs Hudson come in to this? She and Zaharoff were near-contemporaries who had known each other—possibly quite well—back in their wild youth. They could have met since any number of times, in Monte Carlo or elsewhere. Still, I couldn’t help feeling that any actual friendship (or yes, hard as it might be to imagine, any physical attraction) had long since been buried under the weight of his sins. I could see her being forced to put up with his presence as the price of living in Monaco—but like her friend Mrs Langtry, I could also see her stifling an impulse to pull away from his presence.

Were he any less of a power here, Mrs Hudson would treat the man with the sort of polite distraction that makes even an eminent victim feel small. I’d seen her do it, often enough.

Or was I creating a pleasing story around a woman I loved, to convince myself that I really did know her true nature, deep down?

And what about the mysterious Count Vasilev of the manicured facial hair? Loyal friend of the last Czar, but also of Monaco’s own Merchant of Death. Intimate of a ruling family, employer of a possible smuggler, patron of the arts, and a friend to visiting Americans—whose country he wished to make his own, because of an ill daughter.

Round and round went this cast of characters, as the train paused in Nice and Antibes and places along the way. I nearly missed Juan-les-Pins, hearing the repeated name at the last instant and hurling myself through the train’s door before it jerked into motion.

Taxis waited outside. One of them took me to the Hôtel du Cap, the driver speaking over his shoulder all the time in an accent so heavy as to be incomprehensible. I made a noise of vague agreement whenever he paused, hoping to encourage his eyes to stay on the road ahead, and was grateful when we reached the hotel without mishap to ourselves or any of the bicyclists, dogs, trams, beach-goers, or wandering goats along the way. My luck held, in that I got my dress through the lobby and to the safety of my room without having run the gauntlet of astonished stares and ribald comments.

I bathed, happily putting on my own clothing—beach-suitable garments, with no flowers, frills, or the other fillips beloved of 1910’s parasolled and be-flowered ladies—and went downstairs again, stopping by the desk to let them know that I might be gaining a husband.

Then to join the denizens of La Garoupe.