The Closing Window

The brass housing of the strip-chart recorder ticked in steady eighth-inch increments, feeding out two synchronized ribbons of vellum that curled across the steel console like dead ribbons of kelp. In the cramped damp of the Frame 22 Saturation Telemetry Annex, Kalliades did not look at the twin green traces on the oscilloscope; he reached into his canvas satchel, lifted six remaining linear copper cutting charges onto the bench, and laid them end to end beside three coils of yellow detonating cord. If Tymneos managed to dog the deck-six hatches before they synchronized these six charges against the anomaly's standing wave, none of them would live to see the 05:00 deadline on Day Three.

"That's all of it?" Myrinea asked. She stood by the dogging wheel of the annex bulkhead, grease smudging the bridge of her nose where she had wiped condensation from her safety spectacles. "Six sticks and three reels of cord for a two-hundred-thousand-ton floating city?"

"Six eight-ounce shaped charges with five-thousand-meter-per-second RDX cores," Kalliades replied in his flat, even tenor. He took his brass scriber and drew three intersecting arcs directly across the gray enamel casing of Rack Two. "Magazine Three is four fathoms under salt brine. We do not need to cut the whole hull. We only need to fracture the three primary nodal intersections where the anomaly couples with the structural ring."

Behind them, Olynthes pulled a crumpled tin of dried pipe tobacco from his oilskin vest, looked at the flickering fluorescent tube overhead, and pocketed it again with a dry, gravelly wheeze. "Corporate safety manual says ten pounds of high explosive per pontoon bay for a scuttle order. If we sink on three pounds, does my pension still pay out for catastrophic drowning, or do they dock me for improper ordnance utilization?"

"They'll dock your next of kin four hundred drachmas for the unreturned canvas sack," Myrinea said without looking up from the deck schematic spread over the battery bench. "Assuming your lungs don't give out from breathing battery fumes before the titanium folds."

"My lungs are rated for ninety fathoms," Olynthes rasped. "The titanium isn't."

Kalliades adjusted the vernier screw on his brass caliper, measuring the copper liner of the first charge. The metal was cool, five-eighths of an inch wide along its V-shaped apex. "The anomaly is driving an 11.4-hertz standing wave through the longitudinal girders. It uses my cardiac rhythm as its primary phase lock. Every eighty-eight hundredths of a second, the pressure spike passes Frame 40, reflects off the moonpool collar at Frame 26, and returns to the lower pontoon. If we place two charges at the node on Frame 38, two at the Frame 26 expansion joint, and two on the primary ballast manifold, we can disrupt the standing wave precisely when the phase cycles to peak tension."

Nethia leaned forward from the hydrophone console, her fingers resting lightly on the rotary gain dial. The pale green phosphorescence of the cathode tube cast sharp, jittery shadows across her cheekbones. "If the wave collapses while the anomaly is locked to your pulse, what happens to the return echo?"

"The hydro-acoustic energy dissipates into the open trench," Kalliades said. He pulled three brass shims from his vest pocket and set them beside the primer caps. "Instead of compressing the hull inward, the water mass blows outward through the flood valves. The rig remains buoyant on its three remaining legs, and we can launch the survival capsule through the moonpool."

"Provided Tymneos doesn't isolate the emergency breaker board," Myrinea noted. Her pencil tapped against Frame 20 on the blueprint. "He's already running patrols through the cable galleries. He thinks we're attempting an unauthorized extraction before the salvage claim clears the maritime board."

"He has two deck mechanics with pneumatic impact wrenches," Olynthes muttered, rubbing his scarred knuckles. "They aren't soldiers. They're thirty-dollar-a-day ballast tenders who don't want to drown any more than we do."

"They will follow his keycards until the lights go out," Kalliades said softly. He began unspooling the detonating cord, drawing a curved rigging knife across each of the three reels to slice an exact nine-foot length of yellow braided sheath. "Which is why the placement must happen simultaneously. We cannot give him time to trip the central breakers."

He laid the three lengths of cord out on the table, securing each with a strip of waterproof adhesive tape. "Myrinea takes the two charges for Frame 26. You know the structural web better than anyone on this vessel. You seat the copper wedges along the upper shear web of the expansion joint, set the brass shims for a one-point-two standoff ratio, and run the lead down to the dry exhaust trunk."

Myrinea took the two copper casings into her calloused hands, testing their weight with a brief, professional nod. "I'll dog the bypass hatch behind me so Tymneos can't follow down the ladder."

"Olynthes," Kalliades continued, sliding two charges and the second length of cord across the bench to the older diver. "You take Frame 38. You know the access crawlways through the bilge voids from the seventy-four survey. You mount the charges on the transverse stiffeners opposite the moonpool."

Olynthes gripped the charges, his raspy breath hitching once in his chest before settling into a slow, steady draw. "Bilge crawlway hasn't been pumped in six months. I'll be swimming in bilge sludge and hydraulic grease."

"Keep the primer caps out of the water until you crimp them," Kalliades told him. "Do not seat the detonators until the hydrophone tone drops below twelve hertz."

"Understood," Olynthes said, sliding the charges into his deep oilskin pockets.

Kalliades turned to Nethia. She was watching the stylus on the vellum roll as it traced the sixty-eight-beat pulse of his heart against the dark oceanic pressure forty fathoms below. Her hands were motionless now, her breathing slow and measured, exactly as he had trained her during the calibration drill.

"Nethia stays here at the hydrophone rack," Kalliades said. "You monitor the 11.4-hertz harmonic. When the three pairs of charges are seated, I will take the primary trigger line to the ballast manifold at Frame 40. When you see the dual trace line up on the scope—when my pulse and the trench wave reach zero phase difference—you trip the main carrier frequency on Rack Two. That will cut the feedback loop for three seconds."

"Three seconds," Nethia repeated, her voice steady. "Then the acoustic shield drops, and you strike the firing pin."

"Three seconds is enough to burn eighteen feet of primacord," Kalliades said.

For two heartbeats, the only sound in the annex was the low, dry hum of the vacuum tubes and the constant, wet friction of seawater sliding past the exterior titanium plating. The plan was clean, stripped of surplus weight, balanced on six pounds of copper-clad explosive and four sets of hands.

Then the deck plate beneath Kalliades's steel-toed boots jumped two inches straight up.

The concussion did not come through the air; it came through the solid metal frame of the Kymatothia, a savage, grinding screech that sheared twelve hardened steel rivets out of the overhead cable tray in a single violent snap. The green phosphor line on the cathode display spiked vertically, smashing against the top glass bezel before tearing itself into a ragged, white smear of high-frequency noise.

Myrinea caught the edge of the drafting table as the room tilted seven degrees to port, the floor shuddering with the sickening, rhythmic groan of primary load-bearing girders warping under catastrophic compression.

"That wasn't Frame 36," Myrinea shouted over the deafening scream of twisting titanium. "That came from the central keel! The Day Three failure sequence is starting now!"

Kalliades grabbed the remaining charges and gripped the bench edge as a second shock wave hammered through the bulkheads, throwing loose brass tools across the floor. His chronometer read 16:34 on Day One. The anomaly was no longer waiting for the structural fatigue of Day Three; it was pulling the rig into the abyss thirty-six hours ahead of time.