The water beneath the egg knocked with the hatchling's rhythm.
The black-feathered mother answered before she saw where the sound came from. Her chest vibrated against the shell. Below her, dark water trembled in the copper channel and returned the same uneven pattern.
Then it returned it again, exactly.
Jiang struck the channel with his beak.
The copper was warm enough to hurt.
He jerked back. A strand no thicker than wet hair slipped through a seam beside the pipe, black at its center and green where the nursery light touched it.
Aylin crouched without putting her hands near the egg. "It is inside the heating line."
Ilex leaned over Mottle's shoulder to see. "Then we do not cut the line."
Rill had drawn his hook knife already. He stopped with the blade above the copper.
"That feeds six beds," Ilex said. "The storm furnace heats the spine. The channels carry it up. Break this one, and every shell along the lower wall cools."
