A heart was not a ring.
Mara had known it in the abstract since the Founder plate: a ring carried one pulse; a heart carried a world. But she did not understand what that meant until she sat down on the grating of the lowest chamber with notebook II open on her knees and tried to begin.
The heart’s channels, the notebook said, were not one path. They were many, and each served a different load. Some carried light and heat to the fields, the crop domes, the growing hours. Some to the homes. Some to the docks, the landing rings and pumps and cranes. Some to the weather engines, the great machines on Lorn’s Reach that kept the air moving and the rain falling under the domes. Each load drew differently. Each changed through the day and the year. A heart’s channels had to be shaped to carry what each load would draw, and to change as the loads changed.
A heart shaped for the wrong loads, her mother had written, will hunt. It will reach for draws that are not there, and starve the draws that are. It will run hot where it should be cool and cold where it should be warm. Within a day it will unsettle the lamp it was built to steady. Count the loads before you fold a single channel. Count them twice.
