The Leeds family (mother Abby, father George and their four children) have just sat down for dinner with Abby's father, Civil War veteran Grandpa Summerill (Charles 'Chic' Sale) when shots are fired outside, down the street. Gangster Maxey Campo has gunned down two men in cold blood and he makes his getaway through the Leeds' family house, assaulting feisty Grandpa along the way. Crusading District Attorney Whitlock (Walter Huston) is elated at first, having an entire family of witnesses ready to do their civic duty and testify against the racketeers running rampant in the city. Maxey, however, isn't finished with the Leeds and unleashes his forces of fear and intimidation against them, leaving Grandpa as the one patriot to stand against crime.