The pulse passed at the twenty-third minute of the sink, and Sen closed the valve.
She had done it a dozen times since the crews went into the cold side. Open at the pulse, closed when it passed. The valve crew’s supervisor no longer waited for the order. She had her hand on the wheel when the well’s draw began to rise and took it off when the draw fell, and Sen only watched the gauge and said now, under her breath, a half second before the wheel turned.
On the gauge, the valve’s line went from open to closed. The basin’s east half stopped warming. The lattice’s line flattened and held on the three returns.
Seventeen minutes left on the reserve. Most of a night on the clock since the reserve began.
Eshel worked it again on the Cinder link. Twice. The pulses’ spacing, their length, the basin’s remaining capacity to the stop. “At the present spacing,” he said, “the seventeen minutes last into tomorrow afternoon. I can’t say whether the pulses stay spaced like this. If they come faster, sooner.”
Mara looked at the plate. The red stop temperature. Under it, nothing about the ration. It had been a habit since the cold side, a thing Sen did with her eyes on a gauge. If Sen were called away, or slept, or fell, nobody reading the plate would know to close the valve.
