In the heat, the air smells like grease and cinders and tar. Old boxcars sprayed all over with graffiti sit on rusty tracks that go nowhere. Plastic bags and fast-food wrappers, empty cans and bottles litter the ground. Sometimes I think places like this are a preview of the future. All the people will be dead or gone, but their trash will be here forever.

Nobody’s on the road but us. Skylar starts singing “I’ve Been Working on the Railroad,” a song we learned in grade school. It seems like a good one for today. I join in, but I’m off-key as usual. Skylar doesn’t care. She has a beautiful voice and carries the tune for both of us. We finish up with a loud chorus of “Fee fi fiddly i oh.”

Skylar laughs. “Remember when we were in glee club and we had to sing for an assembly and Ms. Faglioni asked you not to sing, but just move your lips?”

I laugh, even though at the time Ms. Faglioni really hurt my feelings, and everyone, including Skylar, laughed at me. But still, it isn’t like I wanted to be a pop singer or anything like that.

We ride along, feeling the heat now. There’s not a single tree in railroad wasteland, and no shade. I want to drink my water but know I should save it for later. But what if I get hyperthermia? Maybe I should take a few sips, just in case.

Like she’s reading my mind—which we both sometimes do with each other—Skylar stops and pulls out her water bottle. I watch her take a long drink, at least half of it. I remind myself that I have an extra bottle and follow her example. Water never tasted so good.

We’ve come to the bad part of the road. The tracks cross a bridge over the Paint Branch, a wide, mostly shallow stream of muddy water that never smells good. A narrow boardwalk runs along one side of the bridge, maybe put there for railroad workers. We get off our bikes and walk them across. The whole time, I worry that a train will come. Something might stick out of the train and hit us. Or the weight of the engine might bounce us off the boardwalk and we’ll fall in the Paint Branch and catch a deadly disease from its polluted water.

I tell myself I’m just making up something new to worry about. If I made a list of my worries, it would stretch from here to California.

We cross without a train coming. The woods close in around us. Leaves block the sunlight, but somehow it’s hotter and more humid in the shade. There’s a horrible smell, like something died.

Skylar is ahead of me. Crows fly up into a tree and perch on its branches, cawing and flapping their wings in a menacing way.