Kaelen stared at the screen, then at Elias. “How did you know?”

“Then we request a full shutdown,” Elias said.

Elias finally turned. He was a lean man with ears that stuck out slightly, a physical joke of his profession. “Sound engineering practice,” he said quietly, “is not about what you can see. It’s about what you refuse to ignore.”

There it was. On the inner face of the secondary cooling shroud, a hairline crack no longer than a fingernail. The 14.2 kHz harmonic was the shroud’s material vibrating at a frequency it was never designed for—the acoustic signature of a flaw that, in another 200 hours of operation, would have propagated, split the shroud, and allowed superheated plasma to kiss the primary magnetic ring. The result would have been a cascade failure: a breach, a containment loss, and the Arc Star becoming a brief, bright star.

Kaelen’s face paled. “But… that’s anecdotal.”

Kaelen’s eyes went wide. “A shutdown? Do you know what that costs? The Arc Star is scheduled to depart for Saturn in 72 hours. A full core cooldown and inspection will take five days. The Captain will have your head.”