Tom Powers, portrayed by James Cagney in what is considered a landmark performance, alongside his partner Matt Doyle, played by Edward Woods, are two resilient youths navigating the harsh realities of life in 1920s Chicago. Raised in poverty and desperation, they find themselves working for the notorious Putty Nose, a fence with dubious intentions. Initially, he offers them a golden opportunity to execute a robbery, promising he will aid them should anything go awry. However, when the robbery goes south, Putty Nose abandons them to face the consequences alone.
As the era of Prohibition takes hold, the duo encounters a formidable new ally in Paddy Ryan, who seamlessly ushers them into the underbelly of the illegal brewing business. The story intensifies with the return of Mike, Tom's older brother, from World War I. Disappointed with Tom's entanglements in the criminal world, Mike confronts him, which leads to a heated argument causing Tom to storm out of the family home. The tension escalates further when the powerful gang leader, Nails Nathan, exploits Tom and Matt to keep rival gangs in check, coercing local speakeasies to exclusively sell their brand of beer.
As Tom delves deeper into the gangster lifestyle, he grows increasingly ruthless. A pivotal moment occurs when he lashes out at his girlfriend, Kitty, infamously smashing a grapefruit in her face in a fit of rage, ultimately forsaking her for the sophisticated and alluring Texan, Gwen Allen. In a lavish night club celebration, fate takes a dark turn when Tom comes across Putty Nose once more, resulting in a harrowing confrontation that ends with Tom taking his life in cold blood.
The narrative shifts dramatically following Nails' untimely demise after a horse accident, igniting a fierce gang war that envelops the city. Despite Paddy’s insistence on going underground to wait out the chaos, Tom’s desire for vengeance propels him forward. However, their determination leads them into a deadly ambush by rival gang members, resulting in Matt's tragic death during a violent shootout. Heartbroken yet fueled by vengeance, Tom embarks on a ruthless quest against his adversaries, methodically eliminating them one by one. But his journey of retribution comes at a high price, as he himself becomes a casualty, collapsing in the pouring rain after suffering severe injuries.
In a shocking climax, Tom’s saga culminates in a harrowing finale when members of his gang abduct him from the hospital, ultimately delivering his bandage-wrapped corpse to his mother’s doorstep, an act that underscores the brutal and tragic reality of a life immersed in crime.
