Tracing the Welded Seam

The heat off the fresh weld still prickled the skin of my forearm, but the vibration in the soles of my boots was what warned me.

It was not the rhythmic expansion of boiler tubes or the deep, hollow surge of brine in the mudflats below. The tremor arrived as a fast, light sequence of taps through the perforated iron grating of Catwalk Seven. Four paces back. Then three. Someone was walking along the outer runner where the handrail bolted to the seawall, stepping on the ball of each foot to kill the noise.

He did not know that silence meant nothing to a deaf stoker who lived on iron.

I did not turn around. I let my hands stay on the frozen valve wheel of the auxiliary relief vent, keeping my shoulders hunched as though I were still staring at the bead of melted slag. With my left elbow, I pinned Master Stoker Carrow's shift logbook tight against my ribs inside my oilskin coat. With my right hand, I reached down my thigh until my fingers closed around the cold knurling of the twenty-four-inch brass spanner hanging from my work belt.

The grating dipped behind me. A sudden shift in weight, six inches to the left.

I threw myself sideways against the casing of the main steam drum.

A heavy steel pry-bar came whistling through the sulfur vapor right where my skull had rested a fraction of a second before. The flat edge sheared through the collar of my canvas coat, biting into the brass stud with a dry, ringing snap that echoed into the hollow bones of my jaw. The blow missed my neck, slammed into the relief valve bracket, and threw a shower of orange sparks across the walkway.

I rolled onto my knees, dragging the brass spanner free of its leather loop.

The man stood crouched across the three-foot catwalk. He was lean and wiry, wrapped in a pipefitter's heavy cowhide apron scorched black across the belly. A pair of tinted cutting goggles sat pushed up against a shock of greasy dark hair, and his gray eyes had the flat, dead stillness of harbor slate. Dark grease smeared his jawline, the same mutton tallow that had coated the sheared pipe in the lower gallery.

One of the Salt Exchange fitters. The warning from Carrow's logbook sprang to mind the instant I saw the oxy-acetylene tips jutting from his leather bandolier.

He did not waste breath shouting threats. He saw the brass wrench in my grip, planted his work boots wide on the grating, and drove the pointed end of the pry-bar straight at my throat.

On a three-foot walkway seventy feet above the rocks, backing away is suicide. If you step back, you give the man with the longer lever the whole sweep of the air.

Instead of retreating, I dropped my center of gravity and surged straight forward along the inside curve of the steam drum.

The pry-bar grazed the grease-crust on my right shoulder, tearing the canvas sleeve down to the linen undershirt. The cold iron scraped skin, leaving a stinging streak of fire, but I had already slid inside his reach. I brought the flat head of Carrow's twenty-four-inch naval spanner up with the full torque of my legs and back, driving the heavy brass boss into the fitter's lower ribs.

The brass hit bone with a dull crunch that shuddered all the way up my arm.

The man wheezed, his mouth tearing open in a silent grimace of agony. He staggered back against the outer railing, his heels skittering over the wet iron lips of the deck plates. But he was tough, hardened by years in the high-pressure flues. Before I could chamber another swing, he swung his left elbow around like a hammer, striking my cheekbone.

The world went white. The dull ringing in my skull fractured into needle-sharp spasms of pain. The taste of copper and ash flooded my tongue.

My boots slid across the greasy grating. My back struck the handrail. Behind me, seventy feet down through the salt fog, the dark breakers of the Great Fog-Tide were smashing against the granite teeth of the seawall, sending up plumes of freezing brine that misted the back of my neck.

He recovered his footing faster than I did. His flat eyes locked onto mine, burning with feral calculation. He dropped the pry-bar into a two-handed thrust, aiming to spear me through the chest and tip my carcass over the low rail into the surf.

If the man wanted me to plead, he had picked the wrong technician. Three ruptured boiler drums over ten years had cured me of listening to anyone on a high gantry.

My left hand found the horizontal copper line running along the boiler drum at hip height. It was the manual purge petcock for the secondary condensate trap. Old Carrow always kept the valve seated with an iron square-nut, meant to be blown out twice a shift to clear caustic boiler sludge and boiling scale from the lower manifold.

I did not raise the wrench to block his bar.

I jammed the jaws of the brass spanner over the square-nut of the purge cock. With my boots braced against the deck seam, I kicked down on the wrench handle with my hobnailed heel.

The valve broke free with a violent screech.

A conical blast of five-hundred-degree scald water and oily black magnetite sludge erupted from the petcock nozzle under eighty pounds of boiler pressure.

The jet hit him square across his leather chest piece and washed upward over his throat, chin, and open mouth.

Even with my destroyed ears, the shockwave of expanding steam hit my diaphragm like a cannon discharge. The scald cloud engulfed the catwalk in a blinding swirl of sulfur, brine, and peeling skin.

The man dropped the pry-bar. His hands flew to his face, clawing frantically at the boiling rust water that had stripped the grease from his skin and blistered his cheeks to raw crimson. He staggered backward through the cloud, howling in agony, his boots slipping uncontrollably on the slick condensate pooling across the iron mesh.

He did not come back for a second pass.

He stumbled against the corner stanchion, caught the rail of the outer emergency escape ladder, and hurled himself over the side into the swirling fog bank below. The rungs vibrated violently under his panicked descent, the frantic cadence fading rapidly down toward the lower dock staging.

I leaned against the quivering steam drum, drawing ragged breaths that tasted of sulfur and scorched tallow. Blood trickled warm from the cut beneath my cheekbone, dripping down my jaw to mix with the sweat on my throat.

My ribs ached, and my shoulder burned where the pry-bar had ripped the sleeve, but Tower Four was still humming.

And that hum was reaching a dangerous, shrill tempo.

Beneath my boots, the floorplates were shaking with high-frequency flutter. Without the welded relief valve functioning, the auxiliary boiler had climbed past its safe operating threshold while we fought. The manifold flues were expanding toward their rupture limit.

I turned to the emergency acoustic bypass junction three paces ahead.

The cast-iron bypass lever stood locked behind its tamper-collar, held fast by a heavy bronze padlock. I pulled Master Stoker Carrow's master conduit key from my belt, jammed its tapered wedge foot under the bronze shackle, and threw my weight onto the iron bar. The bronze staple sheared with a sharp crack, and the broken lock fell away.

I unhooked the four-foot steel cheater pipe lashed across my back harness, slotted it over the stubby bypass handle, and hauled downward with both hands.

The internal diversion gate shrieked as its bronze seat parted.

Deep inside the belly of Tower Four, the surging high-pressure steam found its open path. The violent shudder in the floorplates smoothed out at once, transforming from a jagged death-rattle into the steady, thunderous drone of steam flooding into the lower horn reservoirs. The boiler pressure stabilized, safely diverted away from the blocked relief flue.

I wiped the blood and soot from my eyes with the back of my torn sleeve and stepped over to the ladder hatch where the saboteur had disappeared.

On the iron grating beside the top rung lay an oilskin satchel, torn from his shoulder when he had vaulted over the rail.

I scooped the satchel up and opened the brass flap.

Inside were two unspent cylindrical thermite fuses, thick as rolling pins, packed with magnesium ribbon and sealed with black pitch. Tucked into the side pocket beneath the fuses was a stiff slip of linen paper, stamped with blue official wax.

It was an unrestricted nighttime transit chit through the harbor perimeter gates, issued to Merritt Kroll, Contract Pipefitter, Salt Exchange Conduit Division.

At the bottom of the slip, written in immaculate naval ink, was the signature authorizing the saboteur's passage: Royce Hallowell, Watch Lieutenant, Seawall Bastion Three.

The paper trembled slightly against my soot-caked fingers. The treason was not just a gang of rough dock fitters working for Salt Exchange gold. It had a brass naval collar pinned right to its throat.

I tucked the transit chit into Carrow's logbook, slung the satchel over my shoulder, and headed down the ladder toward the seawall fire-door.