An old man who witnessed a crime is threatened by gangsters.

The Leeds family--Abby and George, their children Sue, Jackie, Donny and Ned, and Abby's father, Private Summerill, a Civil War veteran--witness a gang shooting of an informer and a policeman. The killer escapes through their house and everyone gets a good look at his face. District Attorney Whitlock asks the Leeds to identify the murderer, and they all pick out Maxey Campo's picture and agree to testify at the trial. As soon as the news comes out, however, George is kidnapped from work by Campo's men. The men first offer George a bribe not to testify, and when he refuses to back down, they beat him up. Whitlock puts the family under house detention to protect them and Sue is escorted to work by the police. The family grows restive under the restraint. Donny, the middle son, is determined not to miss his baseball game and sneaks out of the house, enabling the gangsters to kidnap him. They threaten to kill the child if anyone in the family testifies against Campo. Whitlock tries to find Donny, but in the meantime, everyone except Summerill refuses to take the stand. Summerill insists that it is their civic duty to testify, no matter what the cost to them, in order to keep gangsters off the streets. Although Sue claims that no one will believe his testimony as he was drunk at the time, Whitlock decides that they have no choice but to put Summerill on the stand. Just before his turn, Summerill escapes from the courtroom to look for Donny. He walks down the streets of the neighborhood where Donny is being held, playing his fife. Donny hears the instrument and recognizing it, throws his baseball through the window. Summerill brings the police, who shoot it out with the gangsters. Donny is rescued just in time to help Summerill convict Campo in court. Campo is executed.