Moriarty was in a black thinking mood. He chewed little violet pastilles of his own concoction and paced his room, hands knotted in the small of his back, brow set in a crinkled frown.

I was still full of the thrill of jizzwhackery, and minded to pop downstairs to call on Flossie or Pussie or whatever the tiny blonde with the lazy eye said she was called. After the hunting grounds, the boudoir � I'd learned that in India, along with how to keep an eye on your wallet in the back of your trousers while they're draped over a chair.

But the Professor was preoccupied.

The evening papers were in, along with tear-sheets of fuller reports that would be in tomorrow's editions. Sapt was claiming that dangerous Ruritanian revolutionary movements needed to be exterminated. He called upon Great Britain, Ruritania's ancient ally, to join the crusade against insurrection, alleging that the assault upon the Embassy (and his person) had been equally an insult to Victoria and Rudolf. Typical foreign sod, wanting us to fight his battles for him.

Back in Streslau, there had been street skirmishes between Michaelists and Rudolfites. Many arrests had been made, and Sapt was expected to return to his country with information which would lead to a complete sweep of the organised troublemakers.

The packet of photographs lay on our bureau. It seemed that reclaiming this property of a lady had interesting side-effects � Moriarty's imaginary revolution had genuinely to be put down.

"I hope the blasted country don't go up in flames before Irene can cash these chips, Moriarty. She'll get no blackmail boodle out of 'em if they're hangin' from lamp-posts in the public gardens."

Moriarty growled. He left the room, and closeted himelf in the dark, buzzing space where he raised his wasps and plotted the courses of heavenly bodies.

Speaking of heavenly bodies, my eyes went to the packet.

The seal was nice and red and heavy and official.

I remembered the line of Irene Adler's throat, the trim of her calves under silk, the swell of ...

No one had said anything about not examining the merchandise.

I listened out � Moriarty was whistling to his wasps, likely to be absorbed for hours; there was no tread on the stair and Mrs Halifax was ordered to keep all callers away. So, no chance of interruption.

I sat at the bureau, and turned up the gas-lamp to illuminate the blotter.

With a deft bit of penknifery, I lifted the seal intact so it could be re-attached with no one the wiser. My mouth was dry, as if I'd been in a hide for hours, watching a staked-out goat, awaiting the pad of a big cat. I poured a healthy snifter of brandy, an apt accompaniment to this pleasurable perusal.

With a warm pulse in my vitals, I slid the contents out of the packet.

It was like iced water tipped into my lap.

There were photographs. Views of Zenda Castle, with figures on the battlements. One wore a gauzy hat with a dead bird stuck to it, the other a comic opera uniform. Even at distance, I'd recognised the lovebirds. Irene Adler and Colonel Sapt.

"Disgustin'," I blurted.

A sheet of paper was slipped into the sheaf of photographs.

MY DEAR COL. MORAN

I knew you'd not be able to resist a peek at these 'artistic studies'. Sorry for the disappointment.

For what it's worth, you may keep all monies which can be raised from them. If b-------l proves unprofitable, I suggest you license them to a manufacturer of post-cards.

My very best to the Prof. I knew I could rely on him to toss a pebble in the pond, sending out ripples enough to make a maelstrom. An ordinary workman would just have secured the package and been done with it. Only a genius on the level of a Buonaparte could turn a simple task into the prompt for turmoil raised across a whole continent.

Please convey the thanks of another colonel. Being Chief of Secret Police in 'one of the most peaceable, least-insurrection-blighted spots on the map' was not a career with a future. The Elphbergs were intent on retiring him, but now � I fancy � he'll be kept on with an increase in salary.

I expect you to retain the last figure for sentimental reasons, and I remain, dear Colonel Moran, very truly yours,.

I flipped through several more entirely innocent tourist photographs of picturesque Ruritania, until � at the bottom of the stack � I beheld the full face of the American Nightingale. In this final, studio-posed photograph she wore the low-cut bodice she'd affected on her visit to Conduit Street, somewhat loosened and lowered, though � dash it! - artistic fogging around the edges of the portrait prevented complete immodesty. Through the fog was scrawled her spidery autograph, "as ever, Irene". I gulped the brandy, and chewed my moustache for a few moments, contemplating this turn of events.

Behind me, a door opened.

I swivelled in the chair. Moriarty looked at me, eyes shining � he had thought it through, and was unhappy. When the Professor was unhappy, other creatures - animals, children, even full-grown men - tended to learn of it in extreme and uncomfortable manners.

"Moriarty," I began, "I'm afraid we've been stung."

I held up Irene's photograph.

He spat out a word.

And that was how a great shambles broke out in Belgravia, shaking the far-off kingdom of Ruritania, and how the worst plans of Professor Moriarty were exploited by a woman's treachery. When he speaks of Irene Adler, or when he refers to her photograph, it is always as that bitch.