The cradle’s shield door sealed behind her with a long hiss.
Mara had not been inside a cradle since the halfway pulse. Five days. It felt longer. She stood in the frame with the shield door at her back and the replacement heart in front of her, on the cradle’s mount, its seven channels seated, its ribs struck home. Beyond it, through the inspection port in the chamber’s far wall, the old heart sat in its housing, red, with the white line across its face.
The chair was there. On the left of the cradle, facing in. Brisk had carried it up again.
She sat.
On the cradle’s board, a slate panel bolted to the frame at eye height, there was a number. It was a different number from the limit; that was chalked on the frame outside, 60, under the struck 90. This was on the board inside, where she would see it every time she looked up. Written in grease pencil in Sera’s square hand.
58.
The pullout threshold. The number at which Sera would pull her out, whatever the heart was doing. Fifty-eight, two short of sixty. Two beats of margin, so that Mara would be out of the field and through the shield door by the time her count reached the limit.
