If a virulent virus—or even the Rapture—depopulated Earth overnight, how long before all trace of humankind vanished? That's the provocative, and occasionally puckish, question posed by Weisman (An Echo in My Blood) in this imaginative hybrid of solid science reporting and morbid speculation. Days after our disappearance, pumps keeping Manhattan's subways dry would fail, tunnels would flood, soil under streets would sluice away and the foundations of towering skyscrapers built to last for centuries would start to crumble. At the other end of the chronological spectrum, anything made of bronze might survive in recognizable form for millions of years—along with one billion pounds of degraded but almost indestructible plastics manufactured since the mid-20th century. Meanwhile, land freed from mankind's environmentally poisonous footprint would quickly reconstitute itself, as in Chernobyl, where animal life has returned after 1986's deadly radiation leak, and in the demilitarized zone between North and South Korea, a refuge since 1953 for the almost-extinct goral mountain goat and Amur leopard.