A Break in the Fog

The salt fog above the western quay was turning from slate to blinding chalk, a sign that the sun was climbing behind the cloud deck. If the wind from the outer reef picked up before noon, the harbor basin would clear completely.

Kiri'ata unlatched the heavy cedar door of her workshop and shoved it back against the damp stone wall. She needed the harbor charts, her brass dividers, and the tallow markers before the morning watch rotated at Tower Seven.

Paora followed her over the threshold, his heavy boots clumping on the cedar planking. He stopped by the grinding bench, leaned down, and took a long, skeptical sniff of the rag soaking in the wash bucket.

"Pickled turnip brine and lime water," Paora said, his face puckered with disgust. "You grind beacon glass with vinegar, Kiri'ata. No wonder the harbor patrol thinks you are making illicit spirits."

"Vinegar cuts the emery grease," Kiri'ata replied without looking up. She unrolled the Admiralty contour map across the flat oak workbench, weighing down the curled corners with two square lead grinding blocks. "If you intend to sniff my workshop, start with the chimney. Tell me if the coal ash is dry."

"The coal is dry, and the chimney smells like burnt mutton fat from the dock cookhouse three doors down," Paora retorted. He wiped his nose on his woolen cuff. "A foul cook, too. Burns the tallow every morning."

Teuira entered last, latching the door behind her to shut out the harbor clamor. She kept her uniform cloak pinned tight at the shoulder, though her signal badge was turned inward. "The slipway watch has doubled. Governor Tautoru posted twelve marine guards with fixed bayonets along the southern jetty. Every mooring cable in the inner roadstead is chained with lead seals. No skiff moves without an Admiralty pennant."

"Then we cannot tow anything out of the basin," Kiri'ata said.

"If a civilian so much as touches a mooring line, the harbor batteries have orders to fire grapeshot," Teuira said. Her knuckles pressed against the edge of the workbench. "When the dawn fog blinded the signal lanterns, Tautoru stayed the gallows. He refused to hang men in the dark where the fleet could not watch. He wants a public demonstration at noon, and he moved the prisoners to the roadstead to prove the navy holds the basin."

Kiri'ata picked up her brass sector and the curved speculum shard recovered from the blast wreckage. The fragment lay cold and dark against the gray grid of the Admiralty chart. "The Moana-iti was not hit by a rocket. The wood was cold three paces from the hole. It was struck by concentrated solar heat, focused to a point no larger than a copper coin."

She set the shard on the chart's reference scale.

"From the radius of curvature on this glass, the focal length is four hundred paces," Kiri'ata said. "Not three hundred, not five hundred. A mirror ground on a curve of eight hundred paces will focus sunlight at half its radius. Exactly four hundred paces."

Paora leaned over the table, squinting at the ink lines that marked the harbor depths. "And Tower Seven sits on the central bastion. How high is the lantern deck?"

"Two hundred and ten paces above mean low water," Teuira answered promptly. "The lower embrasures are ten paces lower. The gun ports were cleared forty years ago, but the sill beams remain."

"And the tide," Kiri'ata murmured. She reached for the Admiralty tide tables hanging from an iron pin beside the bench. "High water peaked at dawn. The morning ebb drops the basin water level by two fathoms before midday. That lowers every hull in the anchorage."

She took her brass divider, opened the legs to match four hundred paces on the chart's scale, and planted the steel needle directly on the square symbol marked Tower Seven.

With a steady sweep of her wrist, she swung the pencil leg across the blue wash of the inner harbor. A dark arc curved through the anchorage, crossing the shipping lanes like an iron sickle.

"Any vessel along that arc can be hit," Paora noted. He glanced up at the dry cedar rafters. "And Tamatoa swore your roof shingles would burn, Kiri'ata. If he aims at this quay—"

"A bluff to pin us inside our own door," Kiri'ata said, gesturing with her ivory ruler toward the western quadrant. "Look at the angles. Tower Seven's gun port faces southwest. To reach this quay, the mirror needs low western light at four in the afternoon, but the bastion's granite buttress cuts off the sill long before the sun drops that far. He cannot touch this workshop from Tower Seven. He gave us that threat so we would waste the morning watching our own chimney."

"Then where does he strike?" Teuira asked.

"Where the midday sun actually points," Kiri'ata said. "The weapon requires direct sunlight to enter the embrasure."

She picked up an ivory ruler and laid it across the compass rose.

"The morning fog is thinning," Kiri'ata said. "At ten o'clock, the sun sits in the east, behind the tower's rear granite wall. The mirror is blind. At eleven, the light strikes the outer buttress at a grazing angle. The stone frame blocks the beam."

"When does the light clear the sill?" Teuira asked.

"Twenty minutes past noon," Kiri'ata said. "At that moment, the sun reaches forty-two degrees above the southern horizon. Its rays will strike straight down the throat of the southwest gun port."

She aligned the ivory edge with the azimuth of twenty minutes past noon, drawing a sharp black ray from the tower across the harbor. The line ran outward, perfectly straight, until it intersected the four-hundred-pace arc she had drawn.

The point of intersection was marked with a circular black mooring buoy.

Above the buoy, Admiralty clerk ink spelled out a single designation: Barge Nine.

Teuira froze. The blood drained from her face until her weathered cheeks looked as pale as pipe clay.

"What is moored at Buoy Nine?" Kiri'ata asked, looking up from the calculation.

"The old coal hulk," Teuira whispered. "The governor had it cleared two days ago."

"Is it empty?"

"No," Teuira said, her voice dropping to a harsh rasp. "Marama is on that hulk. Tautoru transferred the old net-mender and his two crewmen there at dawn. He placed them under guard in the forward hold."

Paora straightened up from the table, his bushy brows drawing together. "Why put prisoners on a coal hulk?"

"Because the slipway brig was full of seized nets and cordage," Teuira said. "And because the hulk sits directly in front of the governor's terrace. Tautoru wanted the garrison to see the men he caught."

Kiri'ata stared at the black cross on the chart. Her thumb rubbed against the pale, scarred callus where decades of grinding grit had worn away the grain of her skin.

"There is more," Teuira added, her throat tight. "The coal hulk carries ten casks of wet blasting powder in the aft magazine. It was brought into the harbor last month to blow the submerged ledge off the western mole."

"Ten casks," Paora muttered. He tapped his thick fingers against his apron. "If that powder goes up in the noon heat, it will not just break the hull. The concussion will tear the hold into kindling. Nothing inside will survive to answer questions at a tribunal."

The room went quiet except for the drip of condensation from the eaves outside.

"Tamatoa knows where the prisoners are," Kiri'ata said. Her voice remained even, though her fingers gripped the brass dividers until her joints turned white. "He does not need to ignite the timber. He only needs to focus the beam through the hatch onto the iron bands of the powder casks."

"And when the hulk shatters," Paora said, "Governor Tautoru will declare that the civilian conspirators set off their own hidden bomb to escape execution. The fishermen die, the governor gets his treason plot confirmed, and nobody ever looks at the towers."

"The fog," Teuira said, glancing toward the salt-filmed windowpane.

Outside, the gray wool of the mist was tearing into ragged ribbons. Through the opening, a faint streak of pale gold washed across the harbor, glinting on the dark granite cornice of Tower Seven.

"We have two hours," Teuira said. "I can go to the guard post at the mole. I can try to countermand the sentry orders."

"The sentries have the governor's personal wax tablet," Kiri'ata said. "If you intervene without an Admiralty seal, they will put you in irons alongside Marama. Tamatoa is in the tower now. He has the mirror mounted. He is waiting for the noon sun to clear the stonework."

"Then what do we do?" Paora asked. "We cannot tow the barge or arrest the man on the tower. Do we stand on the quay and watch three fishermen burn?"

Kiri'ata turned toward the rear of the workshop.

Resting in a timber cradle against the wall was a disk of cast flint glass, four feet across and four inches thick at the rim. It was a primary condenser lens, ground three years ago for the Great North Beacon before the council ran out of coin to finish the lighthouse. Its surface was clouded with tallow, but underneath lay eight hundred pounds of lead-tempered crystal.

"We cannot move the target," Kiri'ata said, walking to the cradle and stripping back the oilcloth. "So we will catch the light before it reaches the powder."