Chapter Four: The Wing Beneath the Ice

"That number isn't when the city was built. It is the last time it calibrated the sky." Lin Yue's voice came from the depths. "Xiao Yan. You finally came." Lin did not follow. He aimed three instruments of different bands toward the source. The microphone received no sound. Laser vibrometry found no motion. Only the gold grating in his retina resonated. "You are not my father." The voice paused, then laughed gently. "Good. You are learning cross-validation." At the tip of the left wing, a door shaped like a long beak opened. Blue light colder than two hundred degrees below zero poured through. Su's thermometer failed. "Welcome home," Swift said. "First Observer."