“’Course, then you’ve got a guy like me,” Frank went on. “I always said I wouldn’t go home till I could give my old lady something to be proud of. Fifty years later I ain’t never made it back, and it’s not likely she’d still be there waiting if I did.”

From over on the tracks, they could hear the low sound of the train engine starting up and the shrill wail of the whistle. Frank lifted himself up off the grass and made his way over to the train car. The door was open just enough to slip inside. Nate considered again how it might be to jump on next to the old man and find himself, a few hours later, pulling into the station in Anaconda. He could get to his father by nightfall. He let his brain imagine how it would feel to hear his father’s voice, see his face.

“I’m not telling you it ain’t a good idea to go see your dad,” Frank said over his shoulder as he pulled himself up so that he was standing alongside of the freight car. “I’m only telling you, first things first.”

He scrambled on board then, swinging himself up by his one sinewy arm. “Take care of yourself, chum,” Frank called, as the train pulled away, leaving Nate standing there alone on the muddy embankment to make his way back home.

Up until now Nate had been feeling almost resentful of the obligation to complete the science fair project. He could lie on the floor of the implement shed while Naomi fiddled with the sides of the box and the miter saw, and if things didn’t work out all that great (which they didn’t; she was terrible with tools), who cared?

But walking home, it became clear to him: He would build the cloud chamber not for his teacher or for the fair or for a good grade. He’d build it for his father. He and Naomi would make the most amazing science fair project the judges had ever seen.

He imagined the moment, six weeks from now, when the whole junior high school would be assembled in the gymnasium with their projects set out for the judges, and the principal and Mrs. Unger would be up onstage in front of the microphones. He saw his mother standing there— dressed up like she used to be when there was a special event at school—and his little sister beaming. She’d be so excited, he’d need to remind her to stand still. Naomi would be wearing one of her rumpled dresses, but never mind.

And the winner is..., he could hear Mrs. Unger saying. Then his name and Naomi’s would come over the loudspeaker.