Sherlock Sub lit his pipe—waterproof, naturally—and puffed a ring of smoke that dissolved into the fog.
“The barges carried industrial diamonds,” Sub said calmly. “You didn’t want the barges. You wanted the cargo. And you hid them here to divert suspicion.”
He’d noticed the glove’s stitching—a rare waterproof sealant used only in deep-sea industrial fans. And the oil slick wasn’ engine oil; it was a synthetic lubricant for hydraulic thrusters . Someone had built an underwater conveyor—a giant, silent pump—to suck the barges into this lair.
He flipped a switch. A high-frequency pulse screamed from the sub’s speakers—not a weapon, but the precise frequency of the hydraulic pump’s resonance. The drowned warehouse began to tremble. Bricks rained. The pump overloaded, reversing current. sherlock sub
Thorne stared at the churning Thames. “So what now?”
“Brilliant. But now you’re in my tide pool.” Her sub’s claws scraped the St. Mary’s Log ’s hull. “Flood your ballast tanks, or I’ll crack you like a crab.”
The Thames had coughed up a mystery. Three barges had vanished from the Surrey Commercial Docks in as many weeks, leaving only a slick of iridescent oil and a single, sodden velvet glove. Scotland Yard’s river police called it current theft. Sherlock Sub called it a lie. You wanted the cargo
Thorne panicked. Sub smiled. “You forget, Irene. I’m a student of pressure.”
On the surface, as the river police hauled up diamonds and a furious Irene, Thorne asked, “How did you know the frequency?”
His vessel, the St. Mary’s Log , was a retrofitted salvage submarine, all brass periscopes and humming sonar. His “Watson” was a grumpy marine biologist named Dr. Aris Thorne, who’d rather study bioluminescent algae than chase criminals in the murk. Someone had built an underwater conveyor—a giant, silent
Adler-Nemo’s sub was sucked backward into the collapsing warehouse, pinned by a falling barge.
The answer surfaced in the form of a woman’s laugh, echoing through the sub’s hydrophone.