Below the calendar, on a four-inch-wide ledge formed by a horizontal in the cubicle’s framing, stood a bare tin can, its sides lightly freckled with rust. Milgrim leaned forward and studied its contents: a thin strata of nuts, bolts, two bottle caps, paper clips and thumbtacks, several unidentifiable metal components, corpses of small insects. Everything there that could oxidize was lightly, evenly rusted.