The Hiss of Dead Tides

The surface air struck her face with the choking reek of scorched diesel from the skiff's engine.

Soledad spat out the rubber mouthpiece, pulled off her dive mask with a sharp jerk, and seized the iron boarding ladder on the starboard quarter. Her heart slammed against her ribs with the heavy, unhurried cadence of a bilge piston.

Donato Ceballos leaned over the gunwale, his yellow plastic clipboard clamped tight under his armpit.

—Well? —the bureaucrat demanded, impatience moistening the corners of his lips—. Do you sign or do you refuse, Soledad? The port authority's clamshell dredge is swinging anchor at Tierrabomba waiting on the clearance.

Soledad gave him no reply. She climbed the final rung on trembling calves and dropped the stone fragment she had pried loose with the mason's trowel onto the wooden thwart.

The piece measured barely four inches across. It bore a live, rectilinear, razor-sharp edge, yet it was neither colonial freestone nor granite imported as ship's ballast. It was fossilized coral limestone of a slate-gray hue that swallowed the midday glare without casting a single glint. Striking the dry timber of the bench, a bead of dark, viscous slime oozed from its microscopic pores, exuding an icy vapor that smelled of rotten mire and oxidized copper.

Leovigildo Polo killed the compressor with a heavy swipe of his knuckles.

The old fisherman shuffled forward, crouched by the bench, and stared at the fragment without touching it. His cataract-clouded eyes went wide.

—Where did you take this from, girl? —he asked in a raspy whisper.

—Beneath the keel of the San Jerónimo —Soledad replied, undoing her weight belt with clumsy fingers—. It's no reef, Polo. It's a flight of seventeen stairs plunging at a right angle into the bed of the bay.

Ceballos loosed a harsh, hollow bark of laughter that rang false across the flat water.

—A sunken staircase off Bocachica. Naturally. And at the bottom of the steps sits the treasure galleon San José waiting with an open demijohn of rum. Stop spinning romances, Soledad. That is a breakwater block from Arévalo's 1780 rampart works. Dropped off a scow, and the rotten oak simply settled on top of it.

—Arévalo never quarry-dressed blocks to this density, Donato —she cut in with glacial certainty—. And crown masons never carved vertical stairways into silt trenches where rip-tides drown divers.

That night, across the colonial district of Getsemaní, the first collective anomaly unfolded.

At eleven sharp, the stray dogs along Calle de la Sierpe and the alleys of Espíritu Santo fell silent. It was no gradual settling; it was as though a silent, uncontested command had descended upon the courtyards. The animals pressed their ribs against the whitewashed masonry with ears flattened back and muzzles pressed to the floor tiles.

Inside Soledad's home, the patio spigot dripped over the stone basin with a foreign sound: not the metallic ring of municipal aqueduct pressure, but a thick, viscous hiss.

Soledad stepped out into the dark, wetted her index finger in the stream, and touched it to her lips.

The city water tasted of saturated brine and bitter copper. And from beneath the colonial tiles, a low subterranean drone—the exact sixty-cycle pulse she had felt in the underwater chasm—set the window casements humming with a faint, ceaseless vibration.