A young district attorney seeking to prove a case against a corrupt police detective encounters a former lover and her new protector, a crime boss who refuses to help him.
Newly-promoted if none too happily married Howard Brubaker leaves a rowdy company party early with the stunning Catherine, whom it turns out is herself unhappily married — to the boss. They spend an innocent night in New York becoming more and more attracted to each other, so that when Catherine announces she intends to leave her husband and return to Paris Howard asks to go along too.
While diving for sunken treasure, street-smart gumshoe Tony Rome finds the body of a gorgeous blonde, her feet stuck in a block of cement. Soon after, tough guy Waldo Gronski hires him to find a missing woman named Sandra Lomax, and Rome wonders if there's a connection. He sets about trying to locate the woman, and in no time finds himself mixed up with a beautiful party girl and a slippery racketeer.