Read Chapter 31: The Engineer's Gambit

The transmission had barely faded from the speakers when Élise felt it—a wrongness that crawled up her spine like a cold rivulet of sweat. She stood in the comms shack, her fingers still resting on the console where the playback had ended, and stared at the coordinates Vasseur had given them.

"Plot those against the vessel's projected approach," she said.

Duval, hunched at the nav station, did not question her. His fingers moved across the touchscreen, pulling up the enforcement vessel's trajectory from Driftwood's passive sensors—still limited, still grainy, but enough to project an intercept course.

The two lines appeared on the display. They did not meet. They did not even come close.

"Vasseur is wrong," Duval said. He didn't say it like a question. He said it like a man who had just watched a chess piece sacrifice itself and was now trying to figure out what the move meant.

Élise leaned over the display, tracing the coordinate with her fingertip. The point Vasseur had given lay nearly a kilometer off the vessel's actual fuel-line route—in open regolith, far from any hazard, far from any reason a competent engineer would direct an attack.

She pulled up the base's schematics for the *Tyreus*-class enforcement vessels. She knew them. She had done a retrofit certification on one of these hulls eight years ago at the Ganymede orbital yards. The drawings scrolled across her screen, and she looked at the fuel line's external run, then back at Vasseur's supposed weak point.

He'd given them the *Tyreus's* sister design—the older *Archon* class, whose fuel manifold sat in a different position entirely. A detail mistake she might have dismissed as an honest error, except that Vasseur had been chief engineer on a *Tyreus* for the better part of a decade. He could probably draw the vessel's plumbing from memory while blindfolded.

"He's lying," Haddad said from the doorway. The young engineering assistant was pale, sweat beading on his forehead from the corridor fortifications. "He sold us out. They turned him."

Élise shook her head slowly. "He's not lying. He's telling us something."

She replayed the message. Vasseur's voice was steady, almost too steady—the voice of a man reading from a script while a gun pressed against the base of his skull. The code had been simple: numbers buried in innocuous-sounding maintenance reports, references to hours and deck numbers that spelled out the coordinates. But if the coordinates were wrong, the code itself was a lure.

"Run the timing again," she said.

Duval looked up. "Timing?"

"The pauses. The gaps between his sentences. He had to read from a script, but his breathing wasn't controlled. There's a pattern."

She pulled up the waveform of the recording and overlaid it with a timer. The transmission had lasted four minutes and change. Vasseur's pauses came at irregular intervals—at first seeming random, then, when she squinted at the numbers, resolving into something like structure.

Each pause fell at a duration that corresponded to a number. Between the first and second sentences: fourteen seconds. Between the second and third: nine. Then twenty-two. Then three.

Fourteen, nine, twenty-two, three. The sequence repeated twice more, slightly varied, before the transmission closed with a standard corporate sign-off.

"Fourteen letters into the alphabet," she murmured, "then nine, then twenty-two. N-I-V—"

"Niv," Duval said. "That's not a word."

"It's a fragment." Élise's eyes widened. "He's not giving us coordinates. He's giving us a text location. The corporate flight plan manifest—the one they transmitted to all stations when they entered the system."

Duval pulled up the manifest. It was a standard boilerplate document, thousands of lines of legal and technical text. Coordinates for waypoints, fuel consumption projections, passenger and cargo manifests. Useless surface-level data, but dense enough to hide anything.

"Find the passage at line fourteen," she said. "Word nine, letter twenty-two."

The cursor jumped across the document. Line fourteen was buried in a section on emergency override procedures. The ninth word was "containment." The twenty-second letter was "S."

"Keep going," Élise said.

They pulled the next fragment from the pauses: nineteen, five, twelve. S-E-L. Then the third: eleven, fourteen, five. K-N-E.

"SELKNE," Duval read. "Still not a word."

"It's a cipher." Élise pulled up the standard corporate encryption scheme—the one all their distress comms used as a baseline. She fed the string into the decoder, and the output resolved instantly.

"SKELETON KEY," she read aloud. The letters rearranged themselves into the phrase even as she spoke it. "The skeleton key."

"What does that mean?"

Élise was already pulling up the *Tyreus*-class maintenance files. She had access to the corporate database—or she had, before the mutiny had severed most of their links to the outside world. But the files were cached locally, kept in the base's engineering archive for exactly this kind of scenario.

The skeleton key was a maintenance override. Every *Tyreus*-class vessel had one: a sequence of external commands that unlocked the fuel manifold for emergency venting procedures. It was not a weakness in the hull plating or a vulnerable fuel line exposed to attack.

It was a command code.

"He's not giving us a target," Élise said, her voice dropping. "He's giving us a way to drain their tanks from the outside. If we can get a transmitter within range of their hull, we can send the skeleton key sequence and force their fuel system to vent into space."

Duval stared at her. "That's not a weapon. That's a switch."

"Exactly." Élise straightened, feeling the tension in her shoulders ease for the first time since the ultimatum had come in. "We don't need to hit them with drones or laser fire. We just need to get close enough to transmit the code. Their weapons become irrelevant if they have no fuel to power them."

Haddad stepped forward. "And the decoy shuttle?"

"Still useful." Élise's mind was racing now, assembling the pieces. "We launch the damaged pod as cover. While their weapons are tracking it, we slip a drone in with a transmitter on the skeleton key frequency."

"You're gambling everything on a code he may not have been allowed to transmit," Duval said quietly.

Élise looked at the waveform still frozen on the screen. At the end of the transmission, Vasseur had added a final line—a standard phrase, the kind of boilerplate any corporate engineer would use to close a report. But she had seen him work for years, and he never used that phrase. He said it wrong, too: the emphasis on the wrong word, the pause in an unnatural place.

*"Engineering integrity is our highest priority."*

He meant it as a statement of fact, not a promise. And then he had signed off with his name—Dr. Arnaud Vasseur.

The signature code at the end of his name contained a single extra digit. In the corporate system, a signature stamp always ended with the engineer's certification number. Vasseur's was standard, well-known, filed in every base archive. The extra digit transformed it into a different ID entirely: his personal medical override code.

"If they've hurt him," Élise said, "he's flagged it. His signature contains his medical access. If we can pull up his records on the base archive, we can see—

She didn't finish. Duval was already typing. The screen filled with Vasseur's medical file, updated two hours ago by a remote corporate server.

The diagnosis was stark: Cardiotoxin introduced, metabolic inhibitor active, expected time to cardiac arrest—eleven hours.

"A failsafe," Élise said. "They implanted him with a dead man's switch. If we attack the vessel, or if he stops transmitting, the toxin releases. We have eleven hours to either free him or find a way to neutralize the inhibitor."

Eleven hours. The enforcement vessel had given them a twelve-hour ultimatum. Almost perfectly synchronized.

"That's why he gave us the wrong coordinates at first," Élise said. "He wasn't trying to warn us away from the attack. He was buying himself an hour. A margin."

Duval looked at her. "An hour of margin. For what?"

"For us to figure out what he was actually telling us." Élise turned from the screen and began issuing orders. "Run the skeleton key sequence through a diagnostic. Confirm it will work on the *Tyreus* class. Haddad—find me a drone with enough propellant to reach the vessel's hull and back. And Duval—start a search for any chemical compound that could neutralize a metabolic inhibitor."

"We're not engineers of the body," Duval said.

"No," Élise agreed. "But we have a medical bay and a chemistry lab. And we have a friend on that ship who just risked everything to give us a chance."

She glanced back at the frozen waveform on the screen, at the steady line of Vasseur's voice carrying a message no one was supposed to decode.

"Ten hours," she said. "We end this in ten hours. And we take that ship apart to get him back."