The movie begins in 1933, showcasing the notorious bank robber John Dillinger, who is brought to the Indiana State Prison under the guise of a prisoner transfer alongside his partner John "Red" Hamilton (played by Jason Clarke). There, Dillinger and several gang members, including Charles Makley (Christian Stolte), Harry Pierpont (David Wenham), Ed Shouse (Michael Vieau), Homer Van Meter (Stephen Dorff), and Walter Dietrich (James Russo), orchestrate a daring escape with guns smuggled into the prison. This results in a chaotic shootout as Dillinger reveals his identity, using the element of surprise to overpower the guards. In an intense moment, one of the gang members, enraged, fatally beats a guard, leading to further violence as the escape unfolds.
Meanwhile, in East Liverpool, Ohio, Melvin Purvis and his team of FBI agents track Pretty Boy Floyd (Channing Tatum). In a thrilling chase through an apple orchard, Purvis demonstrates his sharpshooting skills by fatally wounding Floyd, marking a significant step in the manhunt for Dillinger.
As Dillinger's gang finds refuge in Chicago, corrupt cop Martin Zarkovich (John Michael Bolger) assures them of protection from the Mafia. Dillinger soon encounters Anna Sage (Branka Katic), a close associate, leading to alliances that prove crucial in their criminal activities.
The narrative shifts to a bold bank robbery in Racine, Wisconsin, where Dillinger and his cohorts don overcoats and bowler hats to blend in. Tension mounts as Dillinger threatens the bank manager while Makley empties the teller cages. Outside, lookout Van Meter remains vigilant, but soon, chaos erupts as police arrive, resulting in a violent shootout as the robbers escape.
In Washington, D.C., amidst a backdrop of frustration, J. Edgar Hoover (Billy Crudup) seeks to escalate the Bureau's campaign against crime, assigning Purvis to spearhead the operation against Dillinger, proclaiming a 'War on Crime.'
Romance blossoms as Dillinger meets Billie Frechette (Marion Cotillard), capturing her heart despite his notorious past. However, their love story is fraught with tension as Purvis's relentless pursuit intensifies. Following a failed ambush at a hotel, Dillinger's cunning escapes continue to leave law enforcement in his dust.
The film unfolds with further heists and escapades, illustrating the gang's reckless lifestyle. Dillinger's daring and charm are pitted against the growing pressure from law enforcement, including key players like Charles Winstead (Stephen Lang). Each heist is laced with palpable danger as Dillinger's illicit activities draw increasing attention.
The climax leads to a dramatic moment in a movie theater showing "Manhattan Melodrama." As Dillinger and his companions leave, they are ambushed by Purvis and his agents. The confrontation culminates in a deadly shootout, resulting in Dillinger being severely wounded. His last words, uttered with poignant emotion, are relayed through Winstead to Billie Frechette: > "Tell Billie for me, 'Bye bye Blackbird.'"
In the aftermath, the film poignantly details the fates of its characters—Purvis's eventual disillusionment and tragic demise, alongside Frechette's later life in Wisconsin. The story encapsulates the thrill and danger of a life on the edge, leaving audiences shaken by the relentless and tragic pursuits of outlaw life.
