AFTER BREAKFAST AT THE INN, I drag my bike up the levee's dewy flank. The sky is like a bruise, clouds drawing to an ominous point. I'm still beat from yesterday, and I've got fifty-something miles to go, ground I'm sure I won't cover before the lurking storm hammers me at last.

I pedal out of Convent past a behemoth collection of towering grain silos; it looks like the world's largest six-pack of malt-liquor tall boys. I cycle past lusterless cliffs of anthracite, sugarcane fields, and sugar refineries so close to oil refineries you wonder how much light, sweet crude you're stirring into your morning coffee. I roll, inadvertently, onto the grounds of a gorgeous industrial facility, its huge carriageways, pipe complexes, and storage sheds all stained a vivid vermilion by some kind of dirt, which is evidently the place's chief product. A pickup truck crunches past me with a few workers in the bed; they're a brilliant red, too. I take a couple of photographs and get back in the saddle. I'm a few hundred yards down the path when a second pickup heaves into view. Before I can dodge it, the driver's door swings open and out steps a uniformed man with a head like a cinder block.

"I heard you been taking pictures," he says.

I admit that this is true.

"Let me see your camera."

"No, thanks," I say.

He sucks his teeth and gets back in the truck and places a call on his cell phone. He reemerges, still sucking his teeth but also trembling at the lip in barely repressed ill will. "I gotta say, it's migh-tee suspicious—you being out here like this."

I shrug.

"Let me see those pictures," he says.

I tell him thanks, anyway.

Another interval of tooth sucking ensues, and then the guy says, "We can do this two ways: Either you erase 'em or I make you wait here a few hours while I call the Department of Homeland Security."

I erase the pictures. Then he makes me scroll through the memory card to be sure. I show him a picture of a house, a parking lot, and a frog. "It's a tree frog," I tell him, adding that if it poses a threat to homeland security, I'd be happy to delete that one as well. I get back on my bike. The pickup makes a U-turn and creeps along behind me for a mile or so. I indulge a detailed fantasy about a day, years down the line, when I'll have a hard time explaining to a child about the lunatic era in American history when it was a matter of federal concern that a man had paused in his travels to take a snapshot of a dirt factory.