RICHARD PRESTON is the author of The Hot Zone (about the Ebola virus), American Steel (about the Nucor Corporation's project to build a revolutionary steel mill), and First Light (about modern astronomy). He is contributor to The New Yorker and has won numerous awards, including the McDermott Award in the Arts form MIT, the American Institute of Physics Award in science writing, and the Overseas Press Club of America Whitman Basso Award for reporting in any medium on environmental issues.