"Pass Christian, Mississippi, 1980: It is three in the morning when Bobby Western zips up the jacket of his wet suit and plunges from a Coast Guard tender into darkness. His dive light illuminates the sunken jet, nine bodies still buckled in their seats, hair floating, eyes devoid of speculation. Missing from the crash site are the pilot's flight bag, the plane's black box, and the tenth passenger. But how? A collateral witness to machinations that...