When rustlers capture the talkative Marigold Prim, her cattle, and her ranch hand, they find her incessant conversation too much to bear and change their plans.
Ronia, who lives with her father and his band of robbers in a castle in the woods, causes trouble when she befriends the son of a rival robber chieftain.
Junior Bender, a burglar turned private investigator for other crooks, is bullied into proving that music industry mogul, Vinnie DeGaudio, is innocent of murder.
The owner of the Sky Blue Inn asks Frank and Joe to commit a fake crime for the benefit of his guests. Unfortunately, a real robbery occurs, and the Hardy boys get the blame.
Thirteen-year-old Sammy's penchant for speaking her mind gets her in trouble when she involves herself in the investigation of a robbery at the "seedy" hotel across the street from the seniors' building where she is living with her grandmother.
Falsely accused of a robbery at the airport, the Hardy boys turn the tables on the real thieves by nabbing them in the act of committing another robbery.