Olivia Thorne wanted to build the first dirigible that could circle the whole world without landing. Right now her prototype couldn't stay awake for a single day. She stood on its narrow deck and watched the power cell needle drop toward empty. The clockwork instruments along the hull slowed. Their brass dials stuttered, then froze. She had lost another set of readings, the fourth time this week. She pulled the spent cell free and dropped it into a growing pile. Each one lasted three hours. Her instruments needed to run a full day to prove the low-pressure envelope was safe. Without a day of clean readings, the Guild would never certify her ship. Without certification, no passenger would ever board. Two years of hidden work sat in a machine that kept falling asleep. Heavy boots climbed the deck stairs. Her father, Cornelius Thorne, came aboard with a newspaper folded under his arm. He was retired now, but he had built clockwork longer than she had been alive. She had learned engineering from stolen books because men like the Guild kept the libraries locked. Her father had never locked a door on her. "You're burning cells like a man burning money," he said. He tapped the frozen dials. "Chemical power dies. It always dies. You know this." "I don't have anything else," Olivia said. "The instruments won't run without a source." Cornelius pushed his round glasses up his nose. He studied the tangle of gears feeding her instrument array. "You keep feeding it more power. Wrong question. Ask how little it needs." He crouched and traced the core wire that ran through the whole system. "This wire is thick. It wastes the current as heat. Thread it fine enough, and a single spark could cradle the load instead of burning it away." Olivia stared at the wire. She had wound it heavy, thinking heavy meant strong. Her father was describing the opposite. One clean spark, held by wire fine as hair, feeding the whole array. They worked through the afternoon. She stripped the thick core out and rewound it with the finest wire in her kit. Cornelius held the tension while she soldered. Her hands shook once. He steadied the joint without a word. At dusk she set a single spark into the new wire. The core glowed and did not burn. The instruments woke. The dials swung up and held steady, drinking almost nothing. She watched the power gauge. After an hour it had barely moved. "It'll run a day," she whispered. "It'll run a week." Cornelius wiped his hands and picked up his newspaper. "Then you'll have your readings." He paused at the stairs. "Get them measured by someone the Guild trusts. Your word won't be enough. It never is, for people like us." Olivia looked at the steady dials. She had solved the power. Now she needed a witness the Guild could not wave away.