Without further discussion, they lengthened their stride toward the big gun. No longer the Biggest Gun in the World, but still pretty big. T.R. was there. He’d know what was going on. Anyway it was the only thing she could see that still had power. Many of the outlying structures—the low steel building where robots filled and prepped the shells, the cooling tower, the natural gas cracking facility where they made the hydrogen—had gone dark. But the gun itself seemed to have at least some systems up and running. The tips of its six barrels and the muffler-like housings that surrounded them were illuminated from below by light shining up the main bore of the big shaft. The steel framework surrounding all that was speckled with lights focused on stairways, catwalks, and hatches. As Jules and Saskia drew closer she could hear the low hum of machinery: pumps moving cold water down to the combustion chamber two hundred meters below and drawing hot water back up, routing it to the cooling tower, which, though darkened, was still burbling and steaming. The higher-pitched whoosh of fans suggested that essential ventilation was still going on. Valves snicked and clunked, gases hissed in pipes, transformers droned. As they got closer yet, Saskia heard voices, mostly male, mostly Texan. Agitated, alert, but controlled.