Sgt. Friday (Jack Webb) and Officer Gannon (Harry Morgan) crack down on a gang of juvenile shoplifters, in "The Big Kids". When teenager Bobby Lassin (Mickey Sholdar) is caught stealing a strange assortment of goods, including diapers, paper clips and a hair dryer, Sgt. Friday delves into the reasons why a boy would take such items. The investigation leads to a mod-clad club, which has a unique set of entrance requirements. The cast includes Roger Mobley as Audie, club leader, Peggy Webber, as Mrs. Lassin, Bobby's mother, Art Balinger as Police Capt. Richey and Richard Crane as Police Sgt. Pearson.