Realizing that his mayoral campaign is in serious trouble, reform candidate Frank Grandell sends his people out to dig up some dirt on Art Hoke, the boss of the city's political machine. Their investigation leads them to Hoke's flunky, nicknamed "Looney Jim". Jim implies that he has some damaging information about Hoke's daughter, but he dies before he can reveal it. Grandell eventually finds out what the "secret" is, however, and must decide whether to use it in his campaign to defeat Hoke's candidate.