No bank was safe during the Depression so long as folks like Pretty Boy Floyd, Baby Face Nelson, Clyde Barrow, the Barker gang, and John Dillinger were on the loose. Hot on their tails, though, was the then-new FBI, the original gang that couldn't shoot straight. However, after seeing innocent bystanders slain and letting Dillinger slip away twice in 24 hours, J. Edgar Hoover whipped the bureau into fighting shape and put the killers out of business in his ''war on crime.'' Burrough (''Barbarians at the Gate'') paints chilling portraits of the dapper Dillinger, the psychopathic Nelson, and the wannabe Barrow, exposing some of their legends as total bunk. Enemies is an amazingly detailed true-life thriller that puts us on a stakeout alongside the feds, inside the banks while bullets fly, and inevitably, next to the criminals' bloody corpses.