The plot of the original film may differ slightly from the back story of "The Days Dwindle Down," but its actions match perfectly with this tale of an innocent murder suspect, who has spent the past thirty years in prison by a corrupt judicial system, which helped to railroad him.
In the current day, Jessica Fletcher (Angela Lansbury) travels to Los Angeles, California, to launch a speaking tour on the talk show circuit regarding her mystery books. At lunch with booking agent Peabody (Tom Dreesen), he suggests that she address some of the various murders which she has helped to solve.
Georgia Wilson (Martha Scott), a hostess at the hotel restaurant, overhears this conversation and later timidly visits Jessica upstairs at her room. "I could be fired for coming up here," Georgia says, preparing to turn around, before Jessica encourages her to visit, to learn that her husband, Sam, has served three decades for a crime which he did not commit: murder.
Sam Wilson (Jeffrey Lynn) reluctantly begins to fill Jessica in on the details, as told by archival flashback scenes, as son Rod Wilson (Art Hindle) enters to inform Jessica that they've explored every avenue. Rod has become a police officer in the hopes of finding evidence to clear his father's name. In the film, the Wilson's have a daughter, Hilda, who is briefly mentioned her but not heard from again.
Jessica naturally accepts the challenge of snooping around town for clues as to what happened that fateful evening many years earlier.
She questions Dorothy Hearn-Davis (Susan Strasberg), the granddaughter of the late Timothy Hearn, a business partner of the late Malcolm Jarvis, whose son, Sidney Jarvis (Richard Beymer), informs Jessica that his mother, Edna Jarvis (Gloria Stuart), has passed. Or has she?
Jessica visits with Jarvis' former private secretary, Thelma Vante (June Havoc), and retired police Lieutenant Richard Webb (Harry Morgan), who handed the original investigation, in the hopes of shedding new light on matters.
While hot on the cold trail of guile, blackmail, intrigue and corruption in the ranks, an unsuspecting Jessica is faced in the night by a gunshot in her hotel room as "The Days Dwindle Down." Debbie Zipp, who would become the recurring Donna Mayberry later in the series, has an early role as the expectant Wilson daughter-in-law.