The shard had come loose on its own.
Doss found it while rigging the jacket, wedged in a crack in the shell’s outer face beside the docking strut: a sliver of plating the size of Mara’s palm, broken from the shell when the lamp failed and held in the crack ever since by the cold. He worked it free with a pry bar and passed it in through the lock. One face was dull grey plating. The other face, the inner one, had a faint silvery skin on it, patchy, thin.
“Mirror iron,” Eshel said. “A little. Grown on the back of the plate before it broke off.”
“Then it’s a test piece,” Mara said. “Before we touch the real shell.”
They set up the test tray in the Tern’s cargo bay. A shallow steel pan on a stand, with a small heater element beneath one end and a coolant line from the Tern’s reserve running to a cold plate beneath the other. The shell’s method in miniature: one end warm, one end cold. Anwen had built it on the flight out from a sketch, because she had wanted to test something before anyone touched a lamp.
Mara set the shard in the tray. Its silver face caught the bay’s work light and threw a faint curved gleam onto the ceiling.
