[1] Accountant and war hero Barry Amsterdam is asked by Chicago newspaper editor David Healey and civic leaders to go undercover and infiltrate the crime syndicate of Arnold Valent, who runs a corrupt insurance business.

Valent is believed responsible for murdering bookkeeper Nelson Kern, who had gone to the newspaper with proof of the criminal activity.

He goes to a nightclub Valent owns, the Maracas, meeting a woman named Sue Morton who helps him gain access.

Valent hires but doesn't trust him, at least until Barry, secretly working with the police, arranges a jewel theft and insurance scam.

But she learns from police who he really is, Sue works with Barry, revealing she is actually the murdered man's daughter, Joyce Kern.