Surfing the Shear

Would the shattered timber hold long enough to carry them across the dead line, or would Gunner Lucano Pereira be forced to light the fuse himself?

From the stone rampart of Fortaleza da Agulha, Lucano pressed his brass rangefinder to his brow. His goal was simple and dangerous: he needed this civilian frigate to clear the gorge on its own momentum before the citadel's inspectors reached his platform. If the ship escaped beyond the sector line, he could log its disappearance as lost in the mist; if it stalled in the gorge, the next order from the high tower would leave him no choice between murder and open treason.

Two miles out, the Esperanza hung at an impossible angle over the abyss. Her port steering spar was splintered into jagged splints, trailing white canvas ribbons across the gray under-cloud. Every gust from the lower valley kicked the frigate’s stern ten degrees to leeward. If her pilot could not right her before the updraft caught her belly, the crosswind would snap her keel in half.

Beside him on the flagged battery deck, Sergeant Martim spat a shred of tobacco leaf into the gun gutter. He kept a fresh lanyard coiled around his wrist, glancing nervously toward the iron signal tower behind them.

"Citadel lookout is flashing the copper lantern again, sir," Martim muttered, his boots scraping dry lime on the flags. "That makes three queries from the commandant. If we do not report a confirmed sinking within two minutes, they will send the provost down with irons."

"Let them flash," Lucano said without lowering the lenses. "Tell them the smoke from our first discharge is still clinging to the damp cedar in the ravine. A second shot into the soup would only waste sixty pounds of crown powder."

"Crown powder costs six maravedis a bag," Martim remarked dryly. "Disobeying the sector interdiction costs your neck. Though with the price of oats in the lower ward, hanging might save on breakfast."

Lucano did not smile, but his jaw relaxed slightly against the brass ocular. "Watch the trim of her starboard yard."

Through the crosshairs, the frigate’s movements looked like madness. Rather than trimming her remaining canvas to crawl away from the fortress, the civilian vessel was pitching her nose down into the teeth of the cloud-shear. Two hundred paces below her keel, the warm updraft from the low valley slammed into the freezing mountain downdraft, churning the mist into a spinning vortex of boiling gray vapor.

No military airship would dare touch that seam. A standard war frigate carried twenty tons of iron plate and two dozen long-guns; hit the shear, and the shearing forces would strip the skin from the ribs.

"What in the Saints' names is that lunatic doing?" Martim squinted over the battery parapet, shading his eyes with a soot-stained sleeve. "He is diving straight into the churn."

"He has no rudder," Lucano observed. His fingers dialed the micrometer wheel, measuring the rate of the frigate's descent against the granite walls of the gorge. "If he stays in the clean air, the yaw will broadside him into the eastern needle. He has only one choice. He is using the pressure lip to steer."

On the Esperanza’s open deck, figures scurried across the canted planks. Even at two miles, Lucano could see the frantic discipline of the crew. Men were dragging water casks and crates of dry ballast from the port hold, heaving them across the slick deck to lash them against the starboard netting.

The frigate dipped. Her starboard rail kissed the swirling boundary of the two air masses.

For a heartbeat, the ship seemed to stop in midair. The turbulence caught her under the starboard chine, rolling her violently forty degrees onto her side. Splintered stays whined across the distance like snapped fiddle strings. A cascade of loose dunnage tumbled from her waist, plunging into the bottomless white mist below.

Martim sucked in a sharp breath through his teeth. "She’s going over. She’ll turtle."

"No," Lucano said, holding his breath as his knuckles locked on the brass frame. "Look at the main boom."

The pilot aboard the Esperanza dropped his remaining foresail flat against the deck and threw the starboard stabilizer wide open. The frigate did not capsize. Instead, the hull grabbed the dense, high-pressure ridge of the cold front like a sled striking hard ice. Skimming the jagged boundary where hot air met cold, the frigate shot forward, riding the curl of the vortex at twice her cruising speed.

The speed was astonishing. The aerostat tore through the mouth of the gorge, slicing beneath the fortress battery's lowest traverse angle. The gun ports of Fortaleza da Agulha could no longer depress far enough to lay a sight on her.

"Mother of God," Martim whispered, his tobacco forgotten. "He is surfing the pressure wave. I have seen fifty captains run the northern gap, but not one with the nerve to ski on raw wind."

"It is not nerve alone," Lucano said quietly, noting the exact angle of the ship's descent on his slate board. "He calculated the thermal displacement to the inch. He knew the downdraft would compensate for his lost port vane."

A rare spark of professional admiration stirred in the artillerist's chest. This was not the clumsy fleeing of smugglers, nor the reckless bravado of privateers. It was master-level navigation, executed on a dying ship with zero margin for error.

Then Lucano's gaze shifted past the fleeing hull to the marker buoys bobbing along the northern ridge.

His slate pencil paused.

Ahead of the Esperanza, the pale blue radiance that permeated the air was thinning out. The ancient beacon on Monte Sombrio had collapsed earlier today, and the auxiliary relays along the gorge were already dark. The frigate was hurtling directly toward the sector boundary, where the active lift field vanished into the dead zone.

Through the glass, Lucano saw the blue glow of the frigate's keel prisms begin to waver. The steady, resonant hum of the grav-cores, audible even across the chasm as a distant chime, fractured into an irregular, shrill screech. The ship's belly dropped three yards in a single violent heave.

"Sir," Martim said, his voice tightening as he pointed a finger north. "Look at her lanterns. The core is losing resonance."

The Esperanza cleared the last granite spur of the fortress gorge, but the price of her escape was instantly visible. Without the triangulation mesh from the fallen towers, her inverted prisms could no longer bite into the gravity gradient. The frigate began to shudder, her bow dropping toward the white ocean of the lowlands as the blue aura around her keel flickered like a candle in a gale.

Lucano lowered his rangefinder. With deliberate, forceful strokes of his steel stylus, he carved the exact elevation, velocity, and boundary coordinates into his slate tablet—capturing the exact terminal boundary where Corveira's gravity grid ceased to exist. It was a priceless prize of raw ballistic telemetry that no chart in the citadel possessed.

He snapped the brass locking cover over the slate and tucked the slate firmly inside his leather artillery tunic.

Heavy bootsteps echoed along the spiral staircase behind the battery deck. The provost guard was ascending.

"Report, Gunner!" the sergeant called, watching the iron door latch rattle. "What do I tell the tower?"

Lucano gripped the firing lanyard, stepped to the breech, and jammed the primer pin crooked so no other man could loose a round without a hammer.

"Tell them the target disintegrated in the shear," Lucano said, turning his back on the cannons. "And tell the armorer I am going below to file the log myself."