Read Chapter 11: The Broken Seal

The rear maintenance hatch was a steel disc set into the train’s tail, its seal stamped with French railway inspection marks. Mercer crouched before it, running his fingers along the rubber gasket. The edge was clean. No scorch marks, no crowbar scars. But when he pressed his thumb against the locking wheel, it spun freely.

“It’s open,” he said. “Or was.”

Camille knelt beside him, her breath fogging the cold metal. The maintenance spur outside had killed the train’s climate control, and the air in the rear carriage tasted of diesel and damp rock. She pulled a penlight from her jacket, sweeping the beam across the hatch’s inner lip. There—a thin smear of grease, fresh enough to shine.

“Somebody came through this way within the hour,” she said. “They didn’t force it. They knew the release sequence.”

Mercer grunted. “Standard French rail maintenance key. But that code changes weekly.” He looked at her. “Whoever did this had inside access.”

“Or the code was passed along.” Camille’s voice was flat. She pocketed the light and stood, scanning the carriage. Empty seats, darkened windows, the hum of emergency power beneath their feet. “Sokolov didn’t get here alone.”

The train had shuddered to a stop on the maintenance spur twenty minutes ago. No platform, no lights beyond the wan emergency strips. Just rough-cut chalk walls and a service tunnel running parallel to the main bore, sealed off by a rusted iron door that had been welded shut years ago—according to the schematics Camille had pulled from the control room. But schematics, Mercer had learned, were optimistic fiction.

He moved to the window, wiping a circle in the condensation. The service tunnel ran alongside them now, a narrow concrete throat lined with cables and pipes. Something glinted at its far end. A reflective strip, maybe. Or a tool left behind.

“He could be out there already,” Mercer said. “Or down the line toward Coquelles.”

“Or he could be waiting for us to think exactly that.” Camille’s eyes were hard. “You said it yourself. The ventilation system is the only route a man his size could use without being seen. If the breach point is out there, he’s either through it already—or he’s baiting us to follow.”

Mercer turned from the window. “You think it’s a trap.”

“I think Sokolov doesn’t run without a plan. And I think whoever briefed him knows this train better than we do.” She gestured toward the hatch. “That seal was broken from the outside. Not from within. Someone came aboard, handed him something, and left before we reached the spur.”

The silver container. The biological agent. Mercer’s jaw tightened. “So he’s already passed it off. That makes him a loose thread, not the target.”

“It makes him a messenger,” Camille said. “And messengers get killed when their delivery is done.”

A distant clang echoed down the track—metal on metal, deliberate. Mercer froze. Camille’s hand went to the holster at her hip.

“That wasn’t the train,” she said.

“No.” Mercer moved toward the hatch, listening. Another clang, closer now. Then a rhythmic splash, like boots moving through shallow water. He pressed his ear to the hatch’s steel. “Drainage channel,” he whispered. “Runs along the spur’s outer wall. Sound carries.”

“How many?”

“At least two. Maybe three.” He pulled back. “Fournier’s men?”

“Or Sokolov’s extraction team.” Camille’s mouth was a thin line. “Either way, they’re not looking for a conversation.”

Mercer scanned the carriage. Emergency equipment lockers lined the far wall—breathing apparatus, flares, a thermal blanket. The maintenance trunk in the ceiling offered a route back toward the passenger cars, but it was narrow and blind. If they crawled in, they’d be fish in a pipe.

“We need eyes outside,” he said. “The service tunnel’s our only clear line. If we can get to the junction box, we can power up the external cameras.”

“The cameras were routed to the operations center. And the operations center is compromised.”

“The cameras are also routed to the train’s internal monitor system.” Mercer nodded toward the driver’s cab at the far end of the carriage. “The backup server runs local. If we can access it, we can see the spur from the roof mounts.”

Camille raised an eyebrow. “You’ve been holding that back.”

“I’ve been saving it.” He moved toward the cab, then stopped. The maintenance hatch behind him groaned—a whisper of movement, barely audible over the train’s idle hum. Someone was pushing against it from the outside.

Camille had her weapon drawn in a heartbeat. Mercer mirrored her. They flattened against the carriage wall on either side of the hatch, guns trained on the seal. The wheel didn’t turn. But a thin line of light appeared at the gasket’s base, then vanished.

“They’re checking the seal,” Camille breathed. “Seeing if it’s been compromised.”

“They’re determining if someone’s used it.” Mercer’s mind raced. If Fournier’s men were securing the perimeter, they’d find Sokolov’s exit route. Or they’d find them. Either way, the train was no longer neutral ground.

The light at the gasket went dark. Footsteps retreated, splashing through the drainage channel. They were moving away.

Mercer exhaled. “They know we’re here.”

“Then we don’t have long.” Camille holstered her weapon and moved to the cab door. “The driver’s monitor is our only eyes. But if we’re trapped in the cab, we’re dead men.”

“We won’t be trapped.” Mercer pulled a compact pry bar from his belt—standard issue for MI6 lock work. He pointed to the maintenance trunk access above them. “That runs the full length of the train, but it’s got a drop hatch at the front coupling. If we time it right, we can exit the nose, work around the exterior, and reach the service tunnel while they’re still sweeping the rear.”

Camille stared at him. “You want to go out there.”

“I want to see what they’re protecting. If they’re sweeping this carriage, they know Sokolov came through here. Which means they know where he went.” Mercer’s eyes were flat. “And I want to know what he handed off before he vanished.”

For a long moment, Camille was silent. Then she moved to the trunk access, pulling the latch. The panel swung open, revealing a dark shaft barely wide enough for a man’s shoulders. She looked inside, then back at Mercer.

“I’ll go,” she said.

“No.”

“Mercer, you’re carrying a fractured hand from the fight in the shaft. You’ll be slow under load. I’ve worked confined routes in Prague for six weeks.” She met his gaze. “I know ventilation systems better than you know your own codebook.”

“You also know Sokolov better than you’ve told me.” Mercer’s words hung in the air. “That connection makes you a liability out there.”

“It makes me the only one who knows how he thinks.” She was already looping a length of cord through the trunk’s internal struts. “You stay. Watch the hatch. If I find the breach point, I’ll signal—two pulls on the line.”

“And if you find Fournier instead?”

“Then you’ll hear the shots.” She gave a thin smile that didn’t reach her eyes. “Make sure they count for something.”

Mercer wanted to argue. But the footsteps had stopped too abruptly, too cleanly—whoever was out there was holding position, waiting. And the train’s dead line was a ticking clock in the center of a tunnel no one knew they were in.

“Two pulls,” he confirmed. “If you’re not back in twenty minutes, I’m coming through after you—protocol be damned.”

Camille nodded. She slipped into the trunk, her frame disappearing into the dark. The panel clicked shut. Mercer counted her footsteps as they faded overhead—four, then eight, then a muffled stop as she reached the coupling point.

The clang returned. Closer now, and accompanied by a low vibration under his boots. Not footsteps. Something heavier. Machinery.

Mercer pressed his ear to the floor. The vibration pulsed in a steady rhythm—hydraulic pumps. Below the carriage, beneath the ballast plates, something was moving. The maintenance spur wasn’t dead.

Someone had turned the gear on.

He moved to the window. At the far end of the service tunnel, a light flickered—amber, then white. It was coming toward them. A service vehicle, running without headlamps, its marker lights just visible in the dark.

Camille wasn’t the only one moving out there. And whatever they were approaching had just started moving toward the train.