Mystery writer Marian Carstairs is hard at work trying to finish her latest novel. Her three children meanwhile are entertaining themselves by trying to solve a murder in their own neighborhood. In between gathering clues, the kids play matchmaker by trying to fix up their widowed mom with the handsome detective investigating the case.
| Actor | Role |
|---|---|
 Peggy Ann GarnerDinah Carstairs | Dinah Carstairs |
 Randolph ScottLt. Bill Smith | Lt. Bill Smith |
 Lynn BariMarian Carstairs | Marian Carstairs |
 Dean StockwellArchie Carstairs | Archie Carstairs |
 Connie MarshallApril Carstairs | April Carstairs |
 James GleasonSgt. O'Hare | Sgt. O'Hare |
 Anabel ShawPolly Walker | Polly Walker |
 Barbara WhitingJo-Ella Holbrook | Jo-Ella Holbrook |
 Shepperd StrudwickMr. Wallace Sanford | Mr. Wallace Sanford |
 Marietta CantyCherrington Housekeeper | Cherrington Housekeeper |
| PPat FlahertyPoliceman Murphy | Policeman Murphy |
 Olin HowlandLuke | Luke |
 Lenita LaneMrs. Flora Sanford | Mrs. Flora Sanford |
 Stanley LoganMr. Cherrington | Mr. Cherrington |
| PPhilip MorrisPoliceman | Policeman |
 James SeayFrank Riley | Frank Riley |