"Why, Dr. Watson! Mrs. Watson!" Mrs. Hudson's face was a picture of combined delight and bewilderment. I didn't blame her in the least, it wasn't often she found me or my wife knocking at her back door!

"May we come in, Mrs. Hudson?" I said sheepishly, lifting my hat. "I'm so sorry to disturb you, but I couldn't think where else to come."

"Of course, Doctor, you're always welcome! Mary dear, it's wonderful to see you." The women embraced fondly. "You've timed things perfectly, as a matter of fact: who d'you suppose arrived not half an hour earlier?"

I didn't need to guess, my eye caught by half of a face peering warily around the kitchen door, topped by a thatch of fair hair. "Billy? Billy Evans, is that you?"

The rest of Billy Evans sidled into view, grinning. The young man had become an Irregular two years ago, after Holmes had caught him lifting my wallet, and he'd been trying ever since, 'just to keep his hand in'. " 'Ow do, Doctor. Missus Watson."

"Hello, Billy, how are you?" Mary smiled.

Billy flushed and looked down at his boots. "But wot brings you two 'ere, Doc? You needin' a place to 'ole up?"

"Something of the sort, lad. Is the kettle on, Mrs. Hudson? This is going to take some time to explain."

~0~

Tonight's visit to Baker Street was only my second since returning to London, the first time to deliver the awful news to Billy and the other Irregulars that their beloved 'guv'nor' had sacrificed his own life to defeat Moriarty. At least the fire that Moriarty's thugs had set hadn't touched the ground floor, and Mycroft had generously paid to have the sitting room restored to its former state, bullet holes and all; but nothing could replace the acid-stained carpet, or the dear old battered furniture which had been through so much with Holmes and I. I therefore spent rather longer than necessary in the kitchen to explain my business there, putting off going upstairs as long as possible. When the moment came, however, Mary's hand was firmly in mine, treading the seventeen steps beside me with Billy and Mrs. Hudson just behind.

I could hardly believe I had not considered consulting what remained of Holmes's papers after the fire until now. Perhaps my reluctance to return had barred my own 'brain attic' to the possibility of finding any help or comfort here... but although walking back into that sitting room was quite as difficult as I had feared, I had little time for reminiscing while the four of us sifted painstakingly through scrapbooks, cartons and filing cabinets for the least mention of diamonds, jewel thefts, or a prizefighter named Sam.

I had started my search with Holmes's 'J' file, smiling in spite of myself as a host of familiar names greeted me from 'Jewel thefts': the lost Agra treasure that had brought Mary and I together so wondrously; the beryl coronet; Charles the First's crown; the blue carbuncle; all meticulously cross-referenced with clients' and criminals' names... Well, that was curious.

"Billy... have you ever heard Holmes mention an 'Ikey Sanders'?"

"Er, can't say that I 'ave, Doc, no. 'Oo is 'e?"

"No idea, but his name is in the margin of the blue carbuncle notes! Holmes must have added this after I finished writing up the case... Pass that scrapbook labelled 'S', will you?" Sabotage, sadism, safe-cracking, saltpetre... "Ah! Sanders, Ikey. Gem cutter, occasional fence. Address: 14 York Street, All Hallows. Known contacts – Good heavens, that's quite the list! Wait on, Maudsley, there's a familiar name..." I rummaged back in the 'J' file for my notes on James Ryder's confession. "Yes, here it is: 'I had a friend once called Maudsley, who went to the bad, and has just been serving his time in Pentonville... He would show me how to turn the stone into money.' "

"So, Sherlock believed this Ikey Sanders was going to cut the carbuncle up for them and fence it?" Mary asked, retying a bundle of newspapers.

"It looks that way. Thank goodness Ryder lost the stone to that goose!" I cast my eye further down the list. A fair number of Sanders's contacts had entries of their own elsewhere in these files, but one in particular caught my attention: Count Negretto Sylvius – a nobleman! A nobleman connected with a jewel fence? Could it be...? Feverishly, I thumbed to the back of the volume.

Sylvius, Negretto, Count. Game-shot, sportsman, man-about-town. Born Venice, 1852. Half-Italian, son of Marcello Sylvius, Venetian merchant, and Lady Julia Tavington of Belcourt Manor, Cambridgeshire. Educated Venice and Cambridge. Address: George's Street, Hanover Square. Known associates...

"My God... It's him!" I whispered, staring at the list. Sam Merton, prizefighter; see also under 'M' and 'Hired thugs'. Count Sylvius had Edward Taylor! Dear heaven, the thought of my poor friend in the employ of such a man was sickening. Never mind Moriarty, the Count deserved a file all to himself!

"Just listen to this, you three! According to Holmes, this Count Sylvius poisoned an elderly woman five years ago, inherited her estate, then gambled it all away in three months!"

"No!" Mary gasped. "Oh, how wicked!"

"Oh, it gets worse," I replied grimly. "He disowned his illegitimate daughter, a Miss Minnie Warrender, twenty years after forcing himself on her mother, who worked in a dockside tavern. He's barely escaped being implicated in numerous robberies; he's also a confidence trickster, and an expert forger of signatures for large cheques."

Billy whistled. "That's one 'ell of a nerve!"

"Nerves of steel," I admitted grudgingly. "The fellow even hunted lions in Algeria before he started going wrong." Or perhaps the thrill of the hunt itself had woken the devil within?

"But why is all of this data just sitting in a scrapbook, for goodness's sake?" Mrs. Hudson frowned. "Why isn't it with Scotland Yard?"

"I don't know... but Holmes clearly hoped to bring Sylvius to justice sooner or later!" And I... I was now in the perfect position to finish what my friend had started! All that was missing was one key witness...

~0~

Mary must have been alerted by my pensive expression, because she made me swear not to stir outside the flat while she and Mrs. Hudson returned to the kitchen for more refreshments, the hour having grown rather late. Billy and I finished reshelving the files, then the lad decided to test the new settee by having a nap, while I paced before the fireplace as softly as I could, too agitated to rest. The pipe rack on the mantel caught my eye, and I hesitated. My own pipe and tobacco pouch were at home in the study... Surely Mrs. Hudson wouldn't mind, as long as I smoked out of the window? Holmes would never have grudged it, I knew, and I needed to calm my nerves somehow.

My friend had used his briar-root pipe the least, but my hand still trembled as I took it down, and I managed to knock the Persian slipper over the edge altogether, which landed with a heavier thud than I would have expected. What on earth...? I bent to pick the slipper up, and my mouth fell open as a large, sparkling object dropped out onto the hearthrug with the loose tobacco. I nearly choked on a gasp, sinking to my knees and scrabbling to retrieve this newest and most alarming piece of evidence.

What in the name of all things holy was Queen Victoria's Koh-i-Noor diamond doing in our flat?!