Tide and Trace

The river gave the dead man until sunset before it took the mud beneath him. For three freezing hours after the midday third bell, Imasha and Tawri had crouched motionless in the sodden cane, watching the Iron Draft's relief watch pace the high levee until the dusk horn sounded across the flats. Now Imasha knelt by the boundary ditch with the brass plumb bob swinging against her wet calf, watching the brown backwash lick the lower rim of Urqu's heel. If the tide rose another finger before she scraped the powder grains from his torn rib, every trace of sulfur would dissolve into river silt, and Pachaq's artillery would have its war by dawn.

Tawri stood knee-deep in the sedge behind her, holding two split-cane poles across her chest like a pair of dry ribs. She had not reached for a knife. She watched the graying ridge where the relief watch had just extinguished its torches for the night.

"Your commander's lookouts walk like iron stoves on grease," Tawri said, her voice pitched beneath the sucking slap of the water. "They are settling into the redoubt with night-glasses. If we strike a match against the wind, they will count the sparks from a mile off."

"I have three vials of olive oil and a tallow wick inside an engineer's shutter box," Imasha said. She set her leather roll onto the driest hump of reeds she could find. Her fingers were stiff with river cold, the skin around her nails gray from dried silt. "A shutter box throws six inches of beam and nothing above the reeds. What I need from you is an anchor."

Tawri stepped closer, the reeds bending under her moccasins without a snap. "An anchor for what?"

"For him." Imasha pointed her thumb toward Urqu's still form. "Pachaq left a notch in the survey lath by his boot. If the body shifts three inches downstream when the current hits the torso, the commander calls it Clan tampering. Then the levee guns fire. The mud is softening around his hips already."

Tawri looked down at the laths, her dark eyes measuring the distance between the corpse and the red boundary cord. "The river does not sign Compact transit vouchers, Imasha. When the lower fork rises, the current will take whatever is not pinned to the shale."

"Then we pin the tools, not the flesh."

Imasha hauled the surveyor’s brass tripod from her pack. She drove the three pointed iron shoes into the hard clay two feet north of Urqu’s ribs, leaning her whole weight onto the foot-pegs until the oak legs bit through the silt. From her coat pocket she pulled a braided copper leveling line, looping it through the brass ring beneath the instrument mount. She knotted the free ends around a set of iron marking pins and drove them into the marsh bed behind Urqu’s shoulders, forming a rigid suspension cradle over the corpse.

Tawri tilted her head, watching the copper wires tighten above the corpse. "It looks like an uninvited marsh crane trying to roost on a drowned man."

"It holds thirty pounds of tension," Imasha said, unbuckling the brass shale-scraper she used for checking culvert mortar from the sheath at her belt. "Which means I can lean across his chest without touching the mud. Pass me the shutter box."

Tawri set the box onto the tripod plate. With a shielded flick of her thumb against a flint cylinder inside the wooden housing, a pencil-thin slit of yellow flame illuminated the dead man’s ribs.

The three cane arrows sat where the killer had hammered them home. Now that the blood had congealed into thick, dark crusts, the pale fringe around the puncture holes showed clearly. The wool of Urqu's tunic had burned away in jagged circles, the cloth edges hardened into black beads of slag.

Imasha pulled a pair of fine steel ballast-tweezers and an unstoppered glass soil vial from the assay tin in her field kit. She gripped the copper line with her left hand, swung her torso out over Urqu's chest, and hovered six inches above the wound.

"Hold the beam on the second shaft," Imasha whispered. "Right at the entry groove."

Tawri tilted the shutter vane. The thin ray of light fell across the torn muscle.

A common blast on the railway line used coarse black grain, ground from crude charcoal, sulfur, and saltpeter. It smelled of rotten pond weeds and burned greasy, leaving a crust of gritty gray cake that stained sheepskin for weeks. What clung to the underside of Urqu’s fifth rib, trapped beneath a sliver of shattered bone, looked nothing like rail powder.

The residue formed a tight, yellow-green glaze. It had not melted into cake; it had fused into tiny, hexagonal wafers no larger than mustard seeds.

Imasha held her breath against the foul stench of stagnant marsh water. She extended the tip of the brass scraper into the split rib. Her shoulder burned under the strain of the cradle, her right forearm trembling against the copper wire. The scraper point touched the edge of the bone. A tiny crumb of residue broke free, clinging to the flat edge of the tool.

Beneath them, the river muttered. A dark tongue of water surged through the sedge, wetting Urqu's waistband. The surveyor's wool jacket grew instantly heavier, the current tugging the soaked hem toward the main channel.

"The tide has found his thighs," Tawri said softly. Her fingers held the brass vane of the shutter box steady, not shaking by a hair. "You have two minutes before the waterline reaches his chin."

"Keep the light still," Imasha said through clenched teeth.

She angled the brass scraper toward the mouth of the glass vial. The tiny wafer slipped over the rim, falling to the bottom with a faint, crystalline click.

She needed an unburned flake from the deeper track. A burned crust proved temperature, but an unburned flake proved origin. The killer had shoved the cane shaft into the meat with a wooden mallet after packing the hollow reed with powder, but the ignition had failed to consume the charge at the bottom of the bore.

Imasha reached deeper. The tweezers grazed the broken cane shaft. Her knuckles brushed Urqu's cold skin. The corpse shifted an eighth of an inch against the silt, the water swirling dark around his armpits.

"Imasha," Tawri warned.

"I have it," Imasha said.

The tweezers closed on a tiny, unburned splinter wedged inside the marrow cavity of the reed. She drew it back through the entry wound with agonizing slowness, clearing the ragged wool without snagging. She dropped the fragment into the vial, slid the cork stopper into place, and drove the wooden plug tight with the heel of her palm.

A surge of muddy foam struck the tripod legs, splashing cold spray across Imasha’s cheek. The river had covered Urqu’s collarbone. In another thirty seconds, the brown flood would close over his mouth.

She swung herself back onto the dry hump of earth, unhooking the copper cables with two swift jerks. The tripod came loose with a wet squelch. Tawri closed the shutter box vane, plunging the marsh back into heavy twilight.

Imasha held the sealed vial up against the pale rim of the western sky.

She unscrewed the stopper by half a turn and drew a tiny draft of air from the vial's neck. The scent struck her palate immediately: not the sour, sulfuric bite of common rock-blaster, but the crisp, medicinal tang of purified turpentine and washed mineral spirits. It was the distinct chemical signature of Dominion naval propellant, manufactured exclusively in the high-pressure steam mills of the southern coast.

Rail contractors could not buy a thimble of it without a signed order from the Admiralty Board.

Imasha pressed the cork back into the glass neck and tucked the vial deep into the inner wool of her coat. Down in the ditch, the black tide covered Urqu's open eyes, sweeping smoothly over the three cane arrows without disturbing the red cord on the boundary post.