Ireland Yard requests Batman's help in solving a baffling series of fog-bound thefts.
Lord Fogg and Lady Peasoup plan to steal a ship-worth of mod clothing material with which they can control the fashion world of Londinium. Fogg and his men subdue Batman, Peasoup and her girls grab Robin and Lady Prudence uses the paralyzing fog on Batgirl.
Battling their way out of Lord Ffogg's fog in the Londinium Tower, Batman and Alfred, in a cab, and Robin in the Batmobile, head for Ffogg's estate to rescue Batgirl. Meanwhile, Lord Ffogg and Lady Peasoup drop lethal fog pellets at Batgirl's feet as Robin, arriving at the estate first, slips toward the house.
Lucy attempts to modernize Rudy Vallee's musical presentation and in doing so transforms the crooner into a Rock 'n Roll sensation.
Jon and Ponch go undercover to investigate a protection racket. Jon poses as a South American diplomat, and Ponch acts as his chauffeur as the two CHP officers attempt to solve an illegal operation that is milking a wealthy man (guest star Rudy Vallee) and his daughter (guest star Mary Frances Crosby).
