The trial ended at its tenth minute, and as Eshel closed the last branch, the collar knocked.
Mara felt it in her boots.
At first there was no sound, only a shock through the gantry’s floor plates, deep, short, coming up from the well below the heart. Then the sound came after it: a low knock, like a fist on a heavy door two floors down, and a long groan behind it, fading.
She had felt the collar knock before. In the dark, while the screws turned. Each time, a settling. This one was larger.
Eshel was reading the collar’s seams. All twelve. “The sliding seams,” he said. “Settling. Under the restored load.” He read them again. “The trial put flow through the heart. The heart’s on the collar. The collar’s carrying the heart’s weight and the flow’s push both, for the first time.” He looked at the slate. “The seams are moving to take it. That’s what they’re for.”
“Is it all right?”
“The seams are all right,” Eshel said. “They’re inside their range.” A pause. “I’m not sure that’s the whole question.”
He did not say what the whole question was. He went back to the slate and read the seams again, and then the jacks’ strain sensors, which he had not read since the seating.
