Private detective Guy Johnson (James Stewart) is well paid to watch over Willie Heywood (Ernest Truex), a wealthy man who likes to drink a bit too much and gets into trouble as a result. However, when Heywood's recent ex-girlfriend Dolores Gonzalez (Cecilia Callejo) makes a public nuisance of herself over their relationship, a drunk Heywood goes to see her. It is a setup. Dolores is being held at gunpoint by a man, and when Heywood enters her apartment, the mystery man kills Dolores and frames Heywood for the murder. The only clue is a half of a dime (United States coin) incorporated into a piece of jewelry that the victim managed to snatch from her assailant. Guy hurries to the scene soon after and hides his client so he can catch the real killer, but both of them are nabbed by the police, tried, convicted and sentenced: Guy to prison for a year, Heywood to be death penalty.