The barbecue was already in motion by the time we arrived, like we’d stepped into the middle of a scene instead of the beginning of one. Marvin’s parents’ backyard stretched wider than it needed to, a rectangle of green with a faded wooden fence and a grill that had clearly seen better summers. The smell of charcoal and lighter fluid hung in the air, mixing with cheap beer and cut grass. Someone—Jeremiah, I think—had alre...