Elias closed his eyes. The drift formula was a monster: Δf = f0 * (αΔT + β(ΔT)²) . He’d memorized it. He did the correction in his head, subtracting 0.0037 seconds from the micro-eclipse window.

Petra let out a breath that was half-laugh, half-sob. “You did it.”

Elias didn’t look at the numbers. He looked at the shadow of the numbers—the afterimage burned into the ferrofluid’s surface for a microsecond before the next cycle. That was the quantum echo. That was the ghost of the past code.

“I’m not wrong,” Elias lied.

But next time was someone else’s problem.