Read Chapter 19: The Cufflink's Code

The control car smelled of burnt rubber and stale coffee. Mercer leaned against the console, one hand pressed against the wet dressing on his side. The fabric of his shirt had gone slick. Not good. He’d lost count of the bleeds that wouldn’t stop.

Camille was at the driver’s window, watching the black mouth of the service tunnel slide past. The autopilot lights blinked in steady rhythm—green, amber, green. No one was steering this thing. Nobody had to.

“Garrick’s not stupid enough to broadcast his endgame and leave us guessing,” she said without turning. “The cufflink. You said it was a gift.”

Mercer pulled it from his pocket. The silver glinted under the panel lights, catching the reflection of the dead conductor’s empty chair. Halloway. The man had worn a matching pair. That couldn’t have been coincidence.

He rolled it between his fingers. The engraving on the face—an interlocking knot, Fournier’s signature mark—was too clean to be ornamental. On a hunch, he pressed the edges with his thumbnail. The bezel gave a quarter turn. A hairline seam appeared along the side.

Camille moved closer. “You knew it opened?”

“Fournier liked secrets with keys.” He worked the seam apart. Inside, no mechanism. Just a disc of brass no larger than a shirt button, its surface etched with a spiral of numerals so fine Mercer had to hold it under the panel light to read them.

“That’s not coordinates,” Camille said, reading over his shoulder. “Too many digits. It’s a frequency.”

Mercer’s pulse picked up. He scanned the console. The train’s comms were jammed—Garrick had made sure of that—but a frequency isn’t a channel. It was a number to call, not a line to open. And numbers could be dialed from anywhere.

He found the portable radio in the dead conductor’s locker. Standard issue, short-range. But if the cufflink was keyed to a specific burst code, the radio might recognize it. He keyed the frequency into the pad.

Static hissed. Camille’s hand strayed toward her weapon. “Who are you calling?”

“I don’t know yet.”

He transmitted the code sequence from the disc. Once. Twice. On the third attempt, the static broke.

A voice came through—low, clipped, carrying the faint accent of someone who’d learned English from textbooks, not streets. “You’re late.”

Mercer’s grip tightened on the radio. “Who is this?”

“The man who’s been paying Fournier’s debts for the last nine months.” A pause. Enough to let that land. “You can call me Remi. You found the cufflink’s true face. That means you’re closer than I hoped—and further than I feared.”

Camille’s eyes cut to Mercer. Her jaw worked, but she held her silence.

“What do you know about the cufflink?” Mercer asked.

“It’s a key. Not to a door—to a location. Fournier designed it so that only someone who understood his work could crack the code. You did. That’s either a good sign or a very bad one.”

“Where does it point?”

Remi exhaled. The sound was tired, like a man who’d spent too many nights waiting for this call. “The old Calais service depot. Eight kilometers north of the main station. Decommissioned in 2003. Off the grid, off the books. That’s where Fournier’s shell company bought its first property. It’s where he built his lab.”

Mercer felt Camille go still beside him. The name Fournier had done that to her before.

“The coordinates micro-engraved on the cufflink—multiple correspond to that depot,” Remi continued. “But the lab isn’t what you think. It’s not a nerve-agent factory. It’s a records vault. Everything Fournier ever touched, every operation he laundered money for, every name he protected—it’s all in those files.”

“Then why send us on a wild chase through a tunnel?” Mercer said. “Why the dead conductor, the fake case, the reroute?”

“Because Garrick wants the files destroyed. He was one of Fournier’s protégés—the oldest one. When Fournier died, Garrick inherited the debt. But the files name him. Every decision he made under Fournier’s shadow is in there. If those records see daylight, Garrick goes down with everything else.”

Mercer’s mind raced. Garrick had been his control officer. The man who’d sent him to Prague. The man who’d known Anna Kessler was going to die.

“And you?” he asked. “Who are you to Fournier?”

The pause stretched long enough that Mercer thought the connection had dropped. When Remi spoke again, his voice was quieter.

“I was his cleaner. When Fournier needed a problem erased, I erased it. I’ve spent two years paying off his debts to the people he wronged. The cufflink was my failsafe. If anyone ever found it, I’d know Fournier’s last play was in motion.”

“Why tell us?”

“Because you’re not meant to survive this train.” Remi’s voice hardened. “Garrick’s plan doesn’t end at a hostage exchange. The autopilot is locked to a collision course. If the hardware key isn’t released before the train reaches Paris, it plows through a decommissioned barrier and into a fuel depot. You’ll be dead before you see the station.”

Camille swore in French. Mercer’s wound throbbed in time with the hum of the rails.

“How do we stop it?”

“You can’t. Not from the control car. The override is manual—a release lever on the underside of the carriage between cars three and four. But it’s welded shut. You’d need the cufflink’s bezel to cut the weld. It’s the same silver alloy, sharp enough if you apply force.”

Mercer looked down at the cufflink in his palm. A key, a tracker, a cutting tool. Fournier had planned for every contingency.

“Why are you helping us?” he asked.

“Because Garrick killed Fournier.” Remi’s voice was flat. “He made it look like a heart attack, but I cleaned up the scene before the coroner arrived. I know the residue patterns. The debt I’m paying isn’t Fournier’s fortune—it’s his murder. You get to that depot, you find the files, and you make sure Garrick never sees the outside of a courtroom.”

Static crackled. The frequency began to fade.

“The depot’s west entrance is a service hatch at rail level,” Remi said quickly. “If you survive the tunnel, that’s where you go. Find Vernet there. He’s the only one who can corroborate what’s in the files.”

The line went dead.

Mercer stared at the radio. His side burned. His mind raced over everything Remi had said—Garrick, the lab, the collision course, a man named Vernet he’d never heard of but who now seemed to be the center of every thread.

Camille held his gaze. “You’re thinking about Prague again.”

“I’m thinking about who else knows about the cufflink,” he said slowly.

The implication hung between them. If Remi knew about the cufflink’s purpose, he might have been the one who told Garrick in the first place. The cleaner’s story was clean. Too clean.

Ahead, the tunnel lights flickered. The train’s speed increased.

The reversal didn’t come as a sound or a flash. It came as certainty, cold and hard in Mercer’s gut.

Remi had known too much. Had known exactly where they were, what they carried, what they’d find. And he’d given them a destination just past a collision course that would end their lives—conveniently keeping Garrick’s secrets buried in the process.

Mercer pocketed the cufflink. “He’s not an ally.”

“You think he’s lying?”

“I think he’s a cleaner.” He met her eyes. “And cleaners follow orders.”