Mama is refusing to cook dinner because she has become hooked on a detective movie marathon on TV. The family is upset about having to go out to dinner at fast food joints, but Bubba and Vint continue to do it so they don't have to eat Naomi's cooking. After they leave, Mama is getting ready for her movies, but Iola enters and asks Mama about some recipes she has to put in envelopes to mail out. Mama promises she will do it, but after Iola leaves, Mama turns to her movies.
The next day Mama is falling asleep while doing her housework, and Iola comes in to say that her Mother is planning to enter a contest at the bank where you can win your weight in pennies. She asks Bubba to help her take Mother to a pasta restaurant. Meanwhile, Vint is trying to fix the lock on the bathroom door, but when he tries to show Mama, it is still broken. Iola comes rushing in and reveals that her Mother is missing. The family decides to help her look for her mother, but Mama stays home by the phone. While waiting, she falls asleep and reams she is a detective in the 1940s.
Detective Harper works from her home with her Girl Friday, Tuesday (Naomi). Visiting to work on her locks is Johnny Deadbolt (Vint). Detective Harper gets something she hasn't had in a while, a client. Rick heiress Miss Neighborly (Iola) and her chauffeur Kid Lucky (Bubba), who also happens to be a small time crook, visit. Miss Neighborly's mother is missing, and Detective Harper has agreed to take the case. After a little investigating, Detective Harper discovers that Mother Neighborly doesn't exist, and Miss Neighborly was signing another name to her own recipes because she didn't think anyone would believe a glamorous heiress could cook. But everyone ends up turning on Detective Harper and join the Mother Neighborly front to all get some of the profits. As Detective Harper is about to meet her demise, the family wakes Mama up and tells her they found Iola's Mother at the Donut Hut after she chased the ice cream man a few blocks. The mystery is solved, but Mama continues to hear the music she heard in her detective dream and swears the next movie marathon she'll watch will be Shirley Temple week.