Bo and Luke learn that a family friend, seemingly innocent little old lady Granny Annie, is operating a small-time counterfeiting ring. Boss Hogg has Granny Annie arrested and confiscates her engraving plates, and sells them to a no-nonsense mobster for $25,000. Bo and Luke set out to clear Granny Annie's name by stealing the plates back and throwing them into a lake ... unaware that the mobster has found out about the theft, assumes Boss is responsible, and plans to kill him. An emotional Rosco pleads to the Duke boys to track down the counterfeiter before Boss suffers a brutal fate.