# Chapter 21: The Saboteur's Equation

**6 years, 119 days until keyhole crossing**

The reactor shield works died at 03:12, when every honest person in the valley was too tired to be suspicious.

It began as a pressure fault in the boron-cement line. That was what the first alarm said, and because the line had failed twice that month, the night crew believed it. They opened the service bay. The second alarm sealed the wrong doors. The third turned the coolant pumps inward.

By the time Jonas reached the remote console, the shield mold was already glowing.

"Kill main feed," he said.

The Suryan operator's hands flew over switches. "No response."

"Manual breaker."

"Crew inside."

On the security feed, three workers ran through steam toward the breaker alcove. One fell. One turned back for him. The third reached the panel and vanished in white light.

The explosion did not look large from Argo. A brief flower on the valley map. A white thermal bloom, then black. In the morning, it was a crater full of wet ash and twisted rebar.

The shield works had taken two years to build.

Hana recalculated for nineteen hours without speaking to anyone except in numbers. When she finally entered command, her face told Mira before the projection did.

"Say it," Mira said.

"We can rebuild," Hana answered. "But not with the old margin."

The model opened. For years the rescue had lived inside a narrow green band called survivable. Kinetic impactors had helped. Mass-driver schedule had been brutal but possible. The valley capture had recovered six months. Now the green band thinned, flickered, and became yellow.

Uncertain.

Jonas stared at the word as if it were an accusation.

"Sabotage path?" Mira asked.

Kael appeared on the link from the valley, soot still streaked across one cheek. "Embedded code in the Suryan pump controller. Written from stolen Earth teaching libraries and Kharos syntax habits. Whoever did it understood both systems."

Liora stood behind him, pale. "That narrows the list."

Kael did not look at her. "Yes."

Aravel joined from the field hospital. "How many dead?"

"Eighty-three confirmed," Kael said. "Likely more under the west wall."

No one filled the silence.

The saboteur had not only destroyed a works. They had solved an equation: what single facility, struck at what hour, could move a planetary model from hope to doubt?

Hana closed the projection. "We need acceleration in every downstream stage. Ice extraction. Shield rebuild. Launch cadence. Surface landing prep. And we need to assume there is another saboteur."

Mira looked at the yellow band.

Uncertain was not failure. That was the cruelty of it. Failure gave permission to mourn. Uncertain demanded more work.

"Then we work," she said.