The tractor returned without trouble. Dale stopped for a planned inspection, and Jonah checked the gauges and the repaired area while Silas looked on. There was dust on the engine and a faint film of ordinary moisture elsewhere, but no new coolant line appeared along the fracture. Jonah recorded the observations before Dale began another pass.
By the third pass, the engine was fully warm. The workload had increased, and the repaired casting was experiencing the sort of expansion and vibration that had eventually exposed Jonah's imperfect practice repairs during winter testing. The boy found himself staring at the same part of the block whenever the tractor approached, almost willing the metal to remain still. When Dale stopped again, there was nothing to report except stable operation.
"You look disappointed," Silas said. Jonah frowned and asked what he meant. The old man pointed toward the tractor. "You keep expecting it to tell you a secret. Sometimes the best answer a machine can give is that there's nothing wrong." Jonah glanced at the dark soil behind the planter and realized his grandfather was right.
The work continued into the afternoon. A light wind blew dust from the rows, the sun warmed the backs of their coats, and Dale covered the first section of the field without stopping for any unplanned repair. Jonah checked the engine at agreed intervals and wrote down the observations even when they had become repetitive. Each uneventful entry mattered because it meant the tractor had done another measurable amount of real work without repeating the failure.
At the far side of the field, Dale finally shut the engine down for a break. He climbed from the seat stiffly, walked to the front of the tractor, and rested one hand on the faded hood. Jonah approached with his notebook, expecting another technical question. Instead Dale said, "Your grandfather says you kept every failed test from winter."
Jonah nodded. Dale looked toward Silas, who was sitting on a low bank with his cap pulled over his eyes, and then back at his son. "I suppose I ought to thank you for all the broken junk you dragged home," he said. Jonah grinned and told him he could thank Big Earl too, since most of the castings had come from the salvage yard.