The bell above the bookstore door rang with a tired little chime, the kind that had heard too many winters. Charlie looked up from behind the counter, one hand resting on a stack of leather-bound volumes that most customers never noticed. To them, Nostalgia was just another rinky-dink, brick and mortar wedged between buildings. To Charlie, it was a hinge in the world—one of many, and one of the last still standing.

Flickering street lamps and police floodlights on the outskirts of the Gowanus Houses illuminate Hoyt Street. White candles tied with red bandanas beside empty Henny bottles surround an 8x10 photo of a baby-faced male positioned on the side wall of Mohammed's Deli. Officers walk their beat. A crowd forms in front of the deli. Staying in their lane, the beat cops move along with their patrol. People in and out of the corner store gaze at the memorial...