Tinker wanted to break the planet's dirt-track speed record in a buggy built with his own hands. Right now that buggy was nothing but junk. Engine parts, wheels, and coils lay scattered across his narrow dorm room floor. He couldn't bolt a single piece in place. The room was too small to even turn a frame around. He sat on his bed and stared at the mess. A tiny cottony creature bounced across the parts, springy legs squeaking with each hop. The little thing landed on his cylinder head and chirped. Tinker almost smiled. "No workspace, no buggy," he said. "No buggy, no record." A knock hit the door. It swung open before he answered. A young man stood there in a rough animal-hide wrap, bare feet in worn sandals. Dirt streaked his arms. Tinker knew him from the work crew behind the school. Bam Bam Rubble. The transfer student who lifted stones most machines couldn't move. "You frown too much," Bam Bam said. He grinned wide. "What's broken?" "Everything," Tinker said. He waved at the floor. "I need room to build. A real buggy. Big enough to tune, test, assemble. This room can't hold half of it." Bam Bam stepped inside and nudged a wheel with his toe. The cottony creature bounced onto his shoulder. He laughed and let it. "The old shed," Bam Bam said. "Behind the dorm. Nobody uses it. Full of broken desks." Tinker shook his head. "I saw it. The door's jammed. The desks are stacked to the roof. It would take a crew a week to clear." Bam Bam cracked his knuckles. "I like hard work." They walked out together. The shed leaned against the dorm's back wall, wide and low, twice the size of Tinker's room. Bam Bam gripped the stuck door and pulled. Rusted hinges screamed. The door tore free in his hands. Inside, broken desks rose in a crooked pile. Bam Bam waded in and started hauling. He lifted whole stacks at once and carried them out. Tinker worked beside him, dragging planks and sweeping dust. The cottony creature bounced between them, chirping, knocking loose screws into a tin. By dusk the floor was bare. Empty, flat, and wide. Tinker stood in the middle and turned a slow circle. He could fit the frame here. The engine. A full test run across the length of it. "This works," Tinker said. His voice cracked. "This really works." "Told you." Bam Bam wiped his hands on his wrap. They carried the parts over, load by load. Tinker laid them out in order for the first time. Chassis here. Wheels there. Engine at the center. He could finally see the whole buggy in his mind. Then he knelt by the engine and froze. He lifted the cracked block and turned it in the fading light. A long split ran down one side. The one part he couldn't build himself. The one part he couldn't afford to replace.

Tinker set the cracked engine block aside and faced a new wall. He had an engine now, pulled from a scrapped SkyRock flyer. But a flight engine spins high and light. It wants air under it. His buggy needed the opposite. It needed low-end grunt to tear a launch out of the dirt. He bolted the SkyRock engine to the bench and ran it. The buggy lurched, coughed, and died. No torque down low. Nothing he could reach would fix that. He tried three more flight engines over two days. Each one screamed at the top and stalled at the bottom. Tinker sat on the shed floor and stared at the dead machine. The workbench behind him held every wrench he owned. None of them could rebuild physics. Elroy Jetson pushed through the door that afternoon. Tinker knew him as the junior rocket pilot, the kid who traded lessons with him—flight theory for throttle timing. Elroy's eyes went straight to the sleek buggy, then to the stalled engine. He didn't waste words. "That's a flyer's engine," Elroy said. "You're asking it to pull. It was built to push." "I know," Tinker said. "It's all I've got." Elroy crouched by the block. He tapped the gearing. "Then stop fighting the engine. Change the gears." He talked fast. "We gear down. Trade top speed for torque at the start. The engine spins where it likes. The buggy gets the grunt to launch." Tinker sat up. "That kills my top end." "For the launch, yeah. You build a second gear set for the straight." Elroy shrugged. "Two setups. One to leave the line. One to run." Bam Bam Rubble ducked in behind him, a steel bar across his shoulders. The caveman had cleared this shed for Tinker with his bare hands. Now he came when work smelled close. "You need something bent?" Bam Bam asked. "I need a new gear housing," Tinker said. "Short. Strong." Bam Bam grinned. "Hard work." They built it that night. Elroy did the math on a scrap of paper. Tinker cut and fit the gears. Bam Bam held the housing steady while Tinker torqued the bolts down hard. The cottony creature bounced along the bench and dropped loose nuts into a tin. Tinker rolled the buggy to the shed's far wall. He climbed in. He fed it throttle slow. The engine caught and held low, growling instead of screaming. The tires bit dirt. The buggy shot forward and crossed the whole shed before he braked. He sat there, breathing hard, grinning like he had at 142 when the rear stepped out. "It launches," he said. Elroy nodded once. "It launches. But you heard it hit the wall of that gear. Short gears, short legs. You got no top speed yet." Tinker looked down the empty shed. He could leave the line now. He still had no way to run flat-out for a record. That was the next build.

The buggy launched now, and it could run. But Tinker found the next wall fast. He opened the throttle wide down the shed's length three times. Each run, the engine screamed hotter. The flight engine was built to fly through cold air. Bolted into a buggy, it had nowhere to dump that heat. On the fourth run, the metal ticked and stank. Tinker killed it before it seized. He laid a hand on the block and pulled back. It burned. He sat on the floor by the workbench and faced the truth. Full throttle cooked the engine. If it seized at record speed, the whole build was scrap. He needed to move heat off the block faster than the engine made it. Elroy pushed through the door that evening, helmet under his arm. The junior pilot traded flight lessons for Tinker's throttle sense, and he read an engine like a race line. He crouched by the block without a word and held his palm near the metal. "It's throwing heat it can't lose," he said. "Up in the air, the wind strips it off. Down here, nothing moves." He stood. "You need more air on it. Or more water through it." "I don't have a pump big enough," Tinker said. Bam Bam ducked in behind Elroy, a split log still in one hand. The caveman had cleared this shed for Tinker with his bare hands when nobody asked him to. He looked at the hot engine, then at the two of them. "What do you need bent?" he asked. Tinker stared at the block. The answer came to him whole. "Copper line," he said. "Lots of it. We wrap the block in coils and run water through them. More surface. More cooling." He grabbed a pencil. "I need it bent tight and even. By hand." Bam Bam set the log down. "Hard work." They built it that night. Elroy figured the flow and the coil spacing on scrap paper. Tinker cut the copper and fit the fittings. Bam Bam bent each loop around the block, slow and steady, his thick hands making the curves match. The cottony creature bounced along the bench and dropped loose clamps into Tinker's open palm. They tied the coils into a small tank and a hand pump. Tinker rolled the buggy to the wall and climbed in. He fed it full throttle and held it. The engine growled hard. He watched the coils. Water moved through them and came out warm, not boiling. He ran it long, longer than it had ever lasted. The block stayed in his hand's range when he touched it. It didn't seize. He sat back, grinning the way he had at 142. "It holds," he said. Elroy nodded. "It holds here." He looked at the short shed wall. "But you've never run it on a real track. Coils shake loose at speed. You won't know till you open it up on dirt."

The coils held in the shed. But Elroy's words stuck with Tinker all week. A short wall was not a track. He had no stretch of open dirt to open the throttle and prove the coils would hold at record speed. Without that run, he could not trust the buggy. And he would not drive it for the record until he did. He went looking for flat ground. Behind the settlement he found it. A long, dry run of packed red dirt, straight and open, edged with scrub. It was no oval, but it was long enough. He paced it off. Plenty of room to open up and hold full throttle. Tinker towed the buggy out at first light. Bam Bam came with him. The caveman had bent every coil on the block by hand, and he showed up without being asked, the way he always did. He wheeled the water tank off the trailer and set it by the buggy. In his other hand he carried a pair of barbell plates from the dorm's old workout bench. He set them on the buggy's tail. "Why those?" Tinker asked. "Weight on the back," Bam Bam said. "Dirt grabs the tires. Loose dirt here." He pressed the plates down. "Keeps the rear planted. You go faster safe." Tinker stared at him, then grinned. It was simple and right. He strapped the plates down tight. He climbed in and pumped the cooling tank to pressure. Bam Bam stepped clear. Tinker rolled to the far end, turned the buggy to face the long run, and set his hands on the wheel. He thought about turn three at Buckhorn Flats, the day he was nine, the driver who lost it. He thought about 142, and how the rear had stepped out, and how he had laughed. He opened the throttle. The buggy launched. The low gears bit and threw dirt. Tinker felt the weighted rear dig in and track straight. He climbed through the gears fast. The engine screamed, but water moved through the coils. Sixty. Ninety. The scrub blurred past. He watched the needle and kept his foot down. One-twenty. The coils drummed against the block, rattling at speed the way Elroy had warned. Tinker felt them shake. He held the throttle flat anyway. One-forty. One-fifty. The buggy stayed glued to the dirt. The coils rattled hard but did not fly loose. The water came out warm, not boiling. The block ran hot but did not seize. One-sixty. The far scrub rushed up. Tinker lifted and braked, sliding the buggy sideways in a wide spray of red dust. It stopped. He sat in the settling cloud. His heart slammed. He laid his hand on the coils. They were hot but tight, every loop still wrapped to the block. They had held at full speed on real dirt. The last wall was gone. Bam Bam ran up through the dust. "It held?" "It held," Tinker said. His voice shook. "All of it." They ran it again that afternoon to be sure, and again the next morning. The coils never shook loose. Word spread through the settlement. A crowd came out the day Tinker went for the record. Elroy was there, helmet under his arm. Bam Bam stood at the tank, his hands ready on the pump. Someone had set up to time the run with a flag at each end. Tinker pumped the tank, faced the long red stretch, and opened the throttle wide. The buggy launched clean. He climbed through the gears with his foot buried to the floor. The dirt roared under the weighted tires. The coils drummed and held. The needle swept past 142, past the number that had chased him for a year, and kept climbing. One-seventy. One-seventy-five. He crossed the far flag flat out and let it ride a long moment before he lifted. When the dust cleared, the crowd was already running toward him. The timers held up the number. He had beaten the planetary dirt-track record. In a buggy he had built with his own hands. Tinker climbed out and put his hand on the hot block one last time. Bam Bam gripped his shoulder. Elroy clapped him on the back. That night they went to the lounge with the pool tables and the stage, and a band played, and Tinker bowled a few frames and listened to the music and let himself be done. He had wanted a machine he built himself to be fastest on dirt in the world. It was. The boy who watched a driver lose control at turn three had built the fastest buggy on the planet, and he had held it flat all the way to the end.