This episode introduces viewers to the residents of Dog City and to Eliot's Muppet world with high adventure. We meet our hero, Private Eye Dog, Ace Hart who with the help of Rosie O'Gravy, chief of police and Eddie, the wet-nosed news pup are out to sniff out clues to the mystery of the disappearing squeaky toys. Dog City is up in arms (paws, actually). Every dog's squeaky toy is disappearing. What dastardly criminal is stealing a dog's best friend - the squeaky toy? Who could be behind this heinous crime? And with what purpose?