While Eliot Shag copes with an infestation of fleas, Bruno breaks in to announce a rumor that cats will be moving into an empty apartment in the building. The incompetent building super is outraged by the possibility and gets into conflict with feline landlady Ms. Fluffé, who summarily fires him. Ace dons a feline disguise to infiltrate the gang, and Badly's master plan is revealed: a plot to drop a flea bomb on Dog City, releasing specially bred fleas which only bite dogs. Ace, working with Bugsy, sets out to save the day, as usual, and Kitty's betrayal is revealed as a ruse.