When mobster Luigi Renaldo goes out of town, his enforcer, Paolo Rienzi decides to bring in a couple of out-of-town men to teach William Norbert, their accountant who tried to quit his job with them, a lesson. They administer a beating a severe beating and Eliot Ness is soon trying to get Norbert to cooperate with the Untouchables. Norbert isn't too keen at first but an attempted hit convinces him to testify against Rinaldo. Norbert has an amazing facility with numbers and essentially keeps the mobs books in his head. As their entire case rests on his testimony Norbert, along with his wife and daughter, are under constant police protection but that doesn't stop Renaldo from going after them.