Public Enemies is a 2009 American biographical mob drama film directed by Michael Mann and written by Mann, Ronan Bennett and Ann Biderman. It is an adaptation of Bryan Burrough's non-fiction book Public Enemies: America's Greatest Crime Wave and the Birth of the FBI, 1933–34. Set during the Great Depression, the film chronicles the final years of the notorious bank robber John Dillinger (Johnny Depp) as he is pursued by FBI agent Melvin Purvis (Christian Bale), Dillinger's relationship with Billie Frechette (Marion Cotillard), as well as Purvis' pursuit of Dillinger's associates and fellow criminals Homer Van Meter (Stephen Dorff) and Baby Face Nelson (Stephen Graham).