Mobster Ma Webster rules her clan with an iron hand, taking charge of all their robberies despite the protests of George Frost, the only member of her gang who is not her son. On Christmas Eve, Ma, George and her sons Eddie, Charlie and Tom, rob the Centre City bank, but are warned to get out of town by her other son Bert, who disdains their criminal activity and is studying to be a lawyer. Ma and the gang go on a crime spree across the states, receiving $300,000 in ransom for kidnapping, and additional cash from various robberies. Aware that the serial numbers on the ransom money have been recorded by federal agents, they arrange with fellow crook Pan to trade the money $100,000 in unmarked bills, but take the bills and kill him instead, They are unaware, however, that the police have found a list of the serial numbers for all Pan's bills in his coat pocket.