Li Jingxi read the rejection letter twice, then set it beside his brass orrery. The Royal Society would hear his claim in three days. His data said a ninth world pulled at Neptune, dragging its orbit off course. His father had shown him that drift when he was seven, calling Neptune the planet that did not want to be found. Now Jingxi had the proof locked in his desk. But one line in the letter ended everything. A rival astronomer would demand independent measurements. Without them, one man's numbers meant nothing. Jingxi worked all night under the planetarium dome. His orrery turned. Every calculation leaned the same way, toward a mass no one had charted. But every number came from his hand alone. In the hall, the painted planets drifted above empty seats. He needed a second instrument, one built by someone else, that reached the same answer. Then no rival could laugh him out. At dawn he crossed the city to the one shop that sold matched things. Cho Cogsmith ran the Emporium, a trader Jingxi had bought lenses from for years. Cho stood at his counter, turning a broken gadget in one hand. Goggles sat pushed up in his hair. Behind him, a clockwork hand rested on a shelf with no body attached. "You look like a man who slept in his coat," Cho said. He did not look up. "I need an orrery I did not build," Jingxi said. "One that tracks the outer planets on its own gears." Cho set the gadget down. He walked to a back shelf and lifted a dark gold astrolabe. A tiny telescope crowned it. Jeweled rings circled a brass sun. Along the outer band ran a ninth set of markings, an orbit past every known planet. "Came in as one of a pair," Cho said. "Maker charted a mass out past Neptune. I thought he was mad." Jingxi's hands shook. He wound the crank. The rings turned. The ninth marker swung wide, exactly where his own numbers said it must. A second instrument. A second maker. The same hidden world. "How much," Jingxi said. Cho named two hundred crowns. Jingxi paid without a word. He had his independent measurement now. The rival's demand was met. But Cho held the astrolabe a moment longer. "One thing," he said. "The maker's dead. Died before he finished. This reads the orbit, but it never fixed the mass. Half his figures are missing." Jingxi looked at the ninth marker, then at the empty numbers etched along the base. The instrument proved a world existed. It could not say how large. A rival would seize that gap and split it wide. "Then I have three days," Jingxi said, "to finish a dead man's work." He carried the astrolabe out into the morning light.