The winter of 1889 drew to a close with a succession of such terrors as I hope never to witness again, yet the true test of my fortitude lay not in the dark vaults of Derbyshire, but within the quiet walls of my own home. Following our return from the Peak District, I had happily resumed the tranquil routine of my medical practice in Paddington, enjoying the domestic comfort that only my dear wife, Mary, could provide.
It was Christmas Eve, exactly one year after the curious affair of the blue carbuncle, and a heavy, suffocating blanket of yellow London fog pressed hard against our parlor windows. Inside, the room was a sanctuary of warmth. A great fire of sea-coal crackled in the grate, casting a cheerful, flickering crimson glow over the festive sprigs of holly Mary had carefully arranged along the mantelpiece.
Mary sat opposite me in her favorite armchair, the firelight catching the soft gold of her hair as she deftly knitted a woollen scarf intended for one of my poorest clinic patients. For an hour or more, the only sounds had been the ticking of the mantel clock and the gentle click of her bone needles. Yet, I noticed a subtle shadow of distraction in her dark eyes, a faint tightening of her brow whenever the wind rattled the window frames.
"John," she said softly, lowering her knitting into her lap. "Do you remember the night you first brought me the Agra treasure? The night that changed our lives forever?"
"Every single moment of it, my love," I replied, leaning forward to take her hand. Her fingers were uncommonly cold. "But why do you ask now, on a night so peaceful?"
"Because the past is a ghost that refuses to be laid to rest," she whispered, her voice trembling slightly. She reached into the pocket of her velvet morning gown and drew out a small, crumpled scrap of parchment. "This was slipped under our front door while you were away at the dispensary this afternoon. It is written in a hand I hoped never to see again."
I took the paper from her, my medical instincts instantly giving way to the cold dread of an investigator. Written in crude, blockish charcoal strokes were the words:
The Sign of Four still breathes, Mrs. Watson. The third share of the Andaman prize was never buried in the mud.
Before I could formulate a word of reassurance, our housemaid, Jane, tapped hurriedly on the parlor door. She entered with a silver tray, looking thoroughly unnerved by the bitter weather outside.
"A delivery for you, sir," Jane stammered, her breath still visible in the drafty doorway. "A rough-looking lad from the docks left it. He said it was life or death for the doctor's lady."
Resting upon the silver tray was an object that made my blood run cold. It was a crude, primitive wooden box, heavily encrusted with dried river salt and the unmistakable, foul-smelling green slime of the Thames marshlands. Tied to the iron clasp with a piece of tarred hemp twine was a single, large goose feather—dyed a brilliant, artificial shade of sapphire blue.
Mary let out a sharp, breathless gasp, her face turning as pale as the snow outside. The long shadow of our earliest adventure had stretched across the years, invading our home on the very eve of Christmas.
