On seeing his adopted goldfish get busted for stealing top-secret documents, Penfold bewails the fact he has never had a pet of his own to love and cherish. He gets his wish when Danger Mouse and Squawk discover the Baron's plans to brainwash the world's pets into becoming his personal army of slaves, and they hand him the responsibility of babysitting the Baron's own pet Nero, having craftily swapped him with a robotic impersonator as a means of getting to the Baron's mind control device - the Pet Whistle! Show less