I ventured into the belly of the holiday-returns beast.

When you order a pair of sweatpants online and don’t want to keep them, a colossal, mostly opaque system of labor and machinery creaks into motion to find them a new place in the world. From the outside, you see fairly little of it—the software interface that lets you tick some boxes and print out your prepaid shipping label; maybe the UPS clerk who scans it when you drop the package off. Beyond that, whole systems of infrastructure—transporters, warehousers, liquidators, recyclers, resellers—work to shuffle and reshuffle the hundreds of millions of products a year that consumers have tried and found wanting. And deep within that system, in a processing facility in the Lehigh Valley, a guy named Michael has to sniff the sweatpants.