A 13-year-old brainiac invents an ingenious listening device, which he uses to bring a crooked city official and his pals to justice
| Actor | Role |
|---|---|
 Edward AndrewsMayor Massey | Mayor Massey |
 John FiedlerCharles Blackburn | Charles Blackburn |
 Lonny ChapmanFred Benson | Fred Benson |
 Eric SheaAlvin Fernald | Alvin Fernald |
 Clay O'BrienShoie | Shoie |
 Kim RichardsDaphne 'Daffy' Fernald | Daphne 'Daffy' Fernald |
 Ted GehringDoyle Reager | Doyle Reager |
 Lynn BordenMiss Pinkney | Miss Pinkney |
 Claude JohnsonMr. Fernald | Mr. Fernald |
| BBebe KellyMrs. Fernald | Mrs. Fernald |
 Maudie PrickettMrs. Hundley | Mrs. Hundley |
 George O'HanlonHerb Evans | Herb Evans |
 Molly DoddMrs. Blake | Mrs. Blake |
 Hal SmithEd Haskins | Ed Haskins |
 Dick WilsonMr. Hodges | Mr. Hodges |
 Larry J. BlakePolice Chief | Police Chief |
 Norman BartoldSam Preston | Sam Preston |
 Judson PrattSgt. O'Halloran | Sgt. O'Halloran |
| BBrian MorrisonShorty | Shorty |
| EEd PrentissCommissioner | Commissioner |
 Rae Dawn ChongGreta | Greta |
| MMarshall KentCity Engineer | City Engineer |
| CChuck SullivantWorm | Worm |
 Peter RenadayReporter | Reporter |
| OOlive DunbarMrs. Barkley | Mrs. Barkley |