The essence of my plan had been sound. Gambling on the principle that there is no honour amongst thieves, I had led Professor Chance to believe that May Dixon had betrayed his trust, anticipating that he would then turn evidence against her. The truth vis-a-vis Lady Duff-Gordon’s diamond ring and Armand Cherpillod’s innocence would surely emerge thereafter.

Admittedly, I came rather closer to being tossed off a sixth-story balcony than I’d have liked, but once they were both in police custody, Chance and May Dixon did, indeed, turn against each other. Unsuspecting of my lip-reading talents, neither could account for my foreknowledge of their burglary other than by secret collusion.

Mr. Cherpillod was released from Wandsworth in due course, and shortly thereafter I was pleased to accept Persephone’s invitation to a soirée in his honour, held at the Bartitsu Club.

When we were introduced he kissed my hand in gratitude, then blushed like a school-girl; the champion Swiss wrestler was, indeed, that rare bird that Persi and her uncle Edward had described, a genuinely humble athlete.

There followed an evening of the most stimulating conversation – one highlight being a hilarious account by William Grenfell, the Baron Desborough, of his adventure swimming the rapids at Niagara Falls – leavened by a lively bout at the rapier and dagger performed by Captain Hutton, the Club’s fencing master, and his pupil, Esme Beringer. Later on, Toupie Lowther favoured us with stirring solo performance of See, the Conq’ring Hero Comes, in Armand’s honour; she possessed a very fine singing voice and evidently also a fine wardrobe of gentleman’s attire.

By eleven o’clock the soirée was winding down and I was just making the rounds of fond farewells when Persephone asked, sotto voce, if I might tarry a while longer. She led me to the back of the hall, then through a doorway, up a short flight of stairs and into a corridor upon whose dark, oak-panelled walls were hung numerous small framed photographs of men and women posing in attitudes of defence. Persephone paused before one of these – it appeared to be a photograph of Theodore Roosevelt posing with Persi’s Uncle Edward, both of them clad in jiu-jitsu garb – and, reaching out with her right hand, gave the frame a quarter-turn to the left. I heard a quiet click and the oak panel swung open.

Following Persi through the secret door, I found myself standing on the sturdy grille of a fire escape platform, overlooking the shadowy gardens of St. Anne’s Church and convent next door.

“So, Judith,” she began, “what do you think of my uncle’s Club?”

“There’s an air of benevolent mystery about it,” I observed, as Persi busied herself fitting a cigarette into an ivory holder. “This evening I’ve met aristocrats, politicians from both sides of the House, actors, soldiers, suffragettes, big-game hunters, artists – it’s a melting pot, which suits me well.”  Just then a flash of movement across the shadowy lawn below caught my eye, and as I peered down into the gloom I saw a pair of foxes racing.

“I’m so glad to hear that,” she said, and she handed me a small card – a Bartitsu Club membership card, in fact, with my own name embossed upon it in silver script.

“Uncle Edward hopes that you will accept this as a token of our thanks,” she beamed. “It’s a lifetime membership. We know that you never accept payment for your ‘little services’, but surely a thorough knowledge of Bartitsu will stand you in good stead …”

Indeed so, as it transpired; but those are other stories.