They went back to the lowest chamber. Sera made Mara walk ahead of her on the red paint, with the line taut, and would not let her look back at the heart.
In the lowest chamber, by the patched valve, Mara sat down on the grating and asked the question she had been afraid to ask.
“Orison. How long does Lorn have?”
The grille was quiet. Then the soft crackle that Mara had learned meant the keeper was searching.
“The lamp’s reserve,” Orison said, “is two local days. That is the heat stored in the outer shell and the regulators, which keeps the lamp burning without its heart. When the reserve is spent, the lamp’s light will fail, over some hours rather than all at once. But it will fail.”
“Two days.”
“Two local days. A local day on Lorn’s Reach is a little shorter than a day on Cinder. I believe. I have a record that it is shorter. I do not have the figure.”
Mara looked at Sera. Sera was looking at her watch.
