Billy Bathgate is a poor Irish American teenager from the Bronx in 1935 who dreams of a bigger life. When he catches the eye of wealthy Jewish mobster Dutch Schultz, he leaves the street behind and joins Schultz’s organization, mostly serving as a gofer while Schul t's charisma and rough edge pull him deeper into the underworld. The film watches him navigate loyalties, temptations, and the pull of belonging as he becomes part of a tightly knit, dangerous family.
Schultz’s world is brutal and uncompromising. He personally commits two brutal murders: his trusted lieutenant, Bo Weinberg, whom Schultz suspects of betrayal after Weinberg is found meeting with rival bosses, is dumped in the water with cement shoes; and his top enforcer, “Big” Julie Martin, is shot dead for stealing $50,000 from the organization, defiantly insisting that he was “entitled” to it. Yet Billy still clings to Schultz as a father figure, marveling at the power and possibility the mob promises, even as the violence hardens him and the lines between protector and predator blur.
The plot thickens when Schultz faces tax evasion charges in upstate New York. He brings his entourage, including Drew Preston, along as he moves into the local community and tries to charm the townspeople with acts of generosity, charity, and even a sham conversion to Catholicism. Schultz appears affable, almost genial, masking the ruthless calculus at the core of his business. While Schultz is at his trial, Billy is tasked with watching [Drew Preston], and the pull of duty clashes with a growing, forbidden affection that Billy begins to feel for her.
Billy’s loyalties are put to the test as Schultz’s plans grow more reckless. Realizing that Schultz intends to have Drew murdered for cheating on him, Billy orchestrates a bid to save her by reaching out to her real husband, wealthy Harvey Preston. Harvey proves resourceful and determined, securing Drew’s safety and whisking her away on a private plane, away from the danger looming over them all.
Despite an acquittal that seems to keep Schultz afloat, trouble returns as the mob’s governing authority, the Commission, becomes wary of the risks Schultz is taking. A new bid for power and money leads Schultz to plot the assassination of state prosecutor Thomas E. Dewey, a move that the Commission will not support. Billy is sent to bribe a member of the Commission, but the attempt fails, and Schultz’s grip on the situation begins to slip. Otto Berman, Schultz’s right-hand man, dismisses Billy but lets him keep the bribe money as a final, reluctant gesture.
As the world starts to collapse, Billy is ambushed and beaten by gangsters loyal to Commission head Lucky Luciano. He is forced to witness Luciano’s men storm Schultz’s safe-haven restaurant where Schultz, Berman, and his henchmen are gunned down in a deadly blaze of violence. The experience leaves Billy battered but alive, and Luciano’s menacing ultimatum lingers in his ears: if he ever speaks of what happened to Dutch, Billy knows that his family could be in danger. Luciano then lets him go, with the envelope of cash that had become part of his uneasy fortune, leaving Billy to decide how much of this world he will carry with him.
