We navigated the labyrinthine servants' stairs, descending into the vaulted stone cellars beneath the mansion. The air grew thick with the smell of coal dust, damp earth, and the distinct, bitter odor of whale oil—the identical scent Holmes had noted on the Wapping fragment and in the Brixton workshop.
The central furnace room was empty, its great iron doors throwing pulsing shadows against the damp masonry. But a large stone flagstone had been pried from the floor, revealing the dark, cramped opening of a medieval heating flue.
"Stay here, Watson," Holmes whispered, throwing off his traveling cloak. "If he attempts to retreat through the furnace hatches, secure him."
Before I could protest, Holmes slipped into the narrow aperture, his dark lantern pocketed as he crawled into the pitch-black stone conduit. I stood in the absolute silence of the cellar, the ticking of my pocket watch marking the final minutes of the dying year.
Suddenly, a muffled shout echoed through the stone vents, followed by the sound of a violent struggle. A heavy metallic object came clattering down the flue, bouncing across the stone floor of the cellar. It was a heavy iron lock-box, its lid partially fractured. From its interior, a brilliant, radiant blue light seemed to pulse against the shadows.
I leaped toward the flue just as a man’s boots emerged from the opening, kicking wildly. I seized the ankles, hauling the intruder out into the dim light of the furnace room. He was a thin, wire-framed man with the pale complexion of a draftsman, his hands blackened with soot and grease.
Holmes scrambled out immediately behind him, his clothes torn but his features alight with victory. "An ingenious attempt, Mr. Silas Lynch!" Holmes panted, pinioned the man’s arms with his knee. "The chief engineer of the Crewe locomotive works, and the secret architect behind every sophisticated burglary that has plagued the nobility this winter."
