Read Chapter 7: The Vanished Doctor

The train shuddered around Mercer, metal groaning against metal, the emergency brakes still locked. He pressed his palm flat against the compartment wall and felt the cold vibration of the ventilation system pushing recycled air through the sealed carriage. Somewhere above them, the French countryside waited. And somewhere below, Dr. Vernet was being led into the dark.

The attendant Lefèvre had given him the underfloor cargo hold. But Mercer had learned long ago that what people told you was rarely the whole truth. The kidnappers knew the train. They had uniforms, keys, an extraction plan. They'd reseal a window, murder an attendant, leave playing cards like breadcrumbs. People who operated that clean didn't use the obvious route.

He moved through the second-class carriage, past slumped passengers and the pale glow of phone screens, and tried to think like a man who wanted to move a doctor off a sealed train without being seen. Not the cargo hold. That was what you wanted people to find. What you actually did was simpler. You went where no one followed.

The toilet at the end of carriage seven was marked out of order. Mercer tried the handle anyway. Locked. He pulled the silver pick from his jacket cuff, worked the mechanism in six seconds flat, and stepped inside.

The compartment was small, functional, and wrong. The mirror was slightly askew. A maintenance panel beneath the sink—painted the same institutional grey as the walls—sat a quarter-inch proud of the surface. Someone had removed it and not seated it properly.

Mercer crouched, worked his fingers under the edge, and pulled.

Behind it, a narrow shaft dropped into darkness. Maintenance access. Big enough for a man to crawl through. Handprints in the dust on the ladder rail, fresh enough to leave skin oil. He pulled out his phone, thumbed on the flashlight, and played the beam across the shaft's interior.

There. On a small ledge where the ladder met the wall, a passport and a phone, placed with the care of someone who wanted them found if things went wrong.

Mercer grabbed them. The passport read DR. ISABELLE VERNET. The photo showed a woman in her late forties, sharp cheekbones, serious eyes. Dark hair. The phone was still warm.

He checked the passport for the stamp. British entry, three days prior. No exit stamps. She'd arrived in London, gotten on this train, and never reached Paris. He scrolled through the phone's recent calls. Twelve missed from an unknown number. One outgoing, placed at 14:32 the day before—the exact time Vernet boarded. He played the voicemail.

*A whisper, barely audible beneath the rattle of the train's wheels: "Vernet. Your files weren't enough. They want the samples. If you don't deliver, the girl in Aberdeen burns."*

Mercer's hand tightened on the phone. Aberdeen. He knew what lived in Aberdeen—the military research annex, the one the informant's file linked to the missing scientists. The girl—a daughter, a niece, someone Vernet loved—was leverage.

Something moved behind him in the shaft.

Mercer spun, dropping the passport, bringing his fists up. A shape filled the opening—broad shoulders, a black cap pulled low, a scarf covering the lower half of the face. But the eyes were unmistakable. Cold. Calculating. The man from the corridor, the one who'd shown Camille's phone with the name SOKOLOV.

Sokolov had found the shaft too. Or he'd been guarding it all along.

Mercer didn't wait. He threw himself forward, driving his shoulder into Sokolov's chest. The bigger man grunted, staggered back into the narrow passage, and Mercer followed, swinging a fist that clipped the jaw. Sokolov's head snapped sideways, but he recovered fast, catching Mercer's next punch in an open palm and twisting.

The corridor filled with the smell of sweat and stale air. Mercer drove a knee into Sokolov's thigh, felt the muscle give slightly, but Sokolov answered with a headbutt that sent white light across Mercer's vision. He tasted blood.

They broke apart, breathing hard, the shaft too narrow for either to fully wind up. Sokolov's hand went to his belt. Mercer tensed, ready for a blade.

Instead, Sokolov pulled out a phone—Camille's phone—and tossed it at Mercer's feet.

"You want it back?" Sokolov's voice was rough, accented, Eastern European. "She's alive. For now. But you're wasting time chasing the wrong doctor."

"Where is Vernet?"

Sokolov's lips curved beneath the scarf. "She was never on this train, English. Not the way you think."

Mercer lunged, but Sokolov was already moving, dropping through a hatch in the shaft floor—a maintenance route to the carriage below. Mercer threw himself after, catching the lip of the hatch, landing hard on a metal platform that rattled with the train's motion.

The underfloor hold. Dark. Cold. The air thick with diesel and damp.

And empty.

Sokolov was gone, swallowed by a shadow between two freight containers. Mercer moved to follow, but something stopped him. A glint of metal, low against the wall where Sokolov had been standing.

He picked it up. A silver cufflink, engraved with the same letters as the one in his pocket. HLF.

And beneath it, folded and forgotten, a seat reservation for carriage four, seat 12B. The passenger name printed in clean block letters: ÉDOUARD LAMBERT.

Mercer pocketed the cufflink and the reservation slip, his mind running. Camille had found a name, a file. But she'd hidden it from him. And Sokolov—whoever he really was—had just given him the same name, leading him to Vernet's passport and phone with the threat that turned her flight into a hostage negotiation.

The doctor wasn't the objective. She was bait. For someone. And the samples—the biological container the kidnappers carried—were the real prize.

Mercer climbed back up the shaft, dragged himself into the toilet, and steadied himself against the sink. His reflection looked back at him, blood seeping from a split lip, eyes hard.

The train gave a violent jerk—the brakes releasing, wheels starting to turn. They were moving again, rolling toward the maintenance spur three kilometers out. Vernet was still somewhere aboard, her passport tucked into his jacket, her phone warm in his fist.

And somewhere in the dark, Sokolov was running with the only answers.