Tom ran through the thickening drizzle, burst through the kitchen door, and yanked the diagram from its pushpin.

Back in the cab, rain now drumming on the roof, he pulled that little yellow fuse. A thin, dark break ran through its metal strip—a tiny bridge snapped in two.

The glow plugs cycled. The dash lit up like a Christmas tree. And the big 6.8-liter engine turned over with a roar that felt like a heartbeat.