Infamous Ma Webster, Blanche Yurka, rules her clan of mobsters with an iron hand and shows no mercy, becoming the terror of Centre City. She tightly controls every plan for the family’s robberies, leaving no room for dissent, much to the dismay of George Frost, J. Carrol Naish, the one member who isn’t related to Ma. George’s protests fall on deaf ears as Ma and her three criminally inclined sons—Eddie Webster, James Seay; Charlie Webster, Richard Denning; and Tom Webster, Paul Kelly—team up with George for a Christmas Eve bank heist in Centre City.
Bert Webster, William Henry, Ma’s more lawful son who studies law, urges his mother and the gang to pull back and leave town to avoid the inevitable arrest tied to a long record of robberies. Yet Ma’s appetite for wealth and the thrill of power pushes the clan onward as they embark on a trans-state crime spree. The spree yields a staggering pile of cash, including a $300,000 ransom from a kidnapping, all while the FBI keeps a close eye on their movements. To offset the risk of marked bills, they strike a deal with Pan, a shady intermediary, exchanging for unmarked cash. They walk away with $100,000 in clean notes, but the lure of keeping the bounty tempts them to violence: they kill Pan and continue their flight, unaware that the FBI now has Pan’s bill ledger and can trace every dollar.
Two federal agents, Scott Langham, Ralph Bellamy, and Ross Waring, Jack Carson, take up the chase. The duo tracks the gang to a southern town where Ma hides as a socialite, but the family flees again, scattering into cheap hotels and small communities as they try to stay one step ahead of the law. When the Christmas holiday returns Ma to Centre City to visit Bert and his newborn baby, the rest of the gang takes advantage of the moment to plan another robbery, this time in a store. The plan misfires: Charlie is shot, and Tom is arrested, shaking the stability of the clan and forcing Bert to step into a courtroom role he hadn’t anticipated.
During Tom’s trial, Bert chooses to represent him, persuading Tom to plead guilty and consent to returning to the city where the kidnapping had taken place. Internal tensions tear the group apart as differing opinions about their fate drive wedges between members. In a fatal moment, George attempts to walk away from Ma’s shadow, but Ma and Eddie end his life to erase any trace of dissent. They then contract a new gang leader, Stitch Torey, to help Tom escape, but the attempted breakout fails, leaving most of the reinforcements dead.
With the core family reduced to Ma and Eddie, they attempt a quieter life, though not a peaceful one. Eddie finds work in a cannery to support them while Ma settles into a neighborly routine, keeping a low profile. Yet Eddie grows restless and careless, setting up a hideout for new associates who join in a planned heist. He steals cans from the cannery and shares them with the newcomers, an act that leads to a fateful car crash during their return trip and the involvement of the police. When investigators discover Eddie’s fingerprints on the cans, they close in, and on Christmas Eve, federal agents storm Ma and Eddie’s home. A violent showdown ensues, and Eddie is killed. In the end, Ma Webster surrenders to the authorities, bringing a tragic close to a long era of crime.
Throughout this saga, the film traces Ma Webster’s iron grip and the shifting loyalties of those around her, from her loyal but increasingly conflicted son Bert to the stubborn, dangerous Eddie, and the relentless pursuit by federal agents who never lose the trail. The narrative unfolds like a tightly wound Christmas tale of crime, repentance, and the cost of living by one woman’s merciless code, set against a backdrop of small-town hotels, busy streets, and the constant hum of pursuit from the nation’s law enforcement.
