Trilogy Part I: One Little Heart was the 8th episode in Season 5 of Quantum Leap, also the 83rd overall series episode. Written by Deborah Pratt, the episode, which was directed by James Whitmore, Jr., debuted on NBC-TV on November 17, 1992.
As the sheriff in a Louisiana town, Sam must deal with two strange deaths and a girl named Abigail Fuller.
August 8, 1955: Sam leaps into the body of Clayton Fuller, the sheriff of a small Louisiana town who's also the father of young Abigail Fuller (Kimberly Cullum). Abigail is accused by a local townswoman named Leta Aider (Mary Gordon Murray) of killing her husband, Deputy Sherriff Bert Aider, who succumbed to a heart attack, and their daughter Violet. Leta is the only surviving member of her deceased family and believes Abagail to be cursed.
Leta, who is unstable, blames Abigail for her husband's death, and that of her daughter Violet, after Abigail had been the last person to see Violet before she disappeared and presumably killed by a pack of dogs two years before.
Sam's mission is to save young Abigail from the raging wrath of Leta, who winds up cornering her in the Fuller house, demanding that she confess to the crimes of murder of her husband and daughter. In the original timeline of events, Abigail died in a house fire after Leta set it ablaze with her in it on the night of August 8, 1955.
Sam visits the mental hospital where Clayton's wife, Laura Fuller, is hospitalized in hopes of trying to get more information about Leta, who had two years earlier a heated argument with her, insulting her and calling her crazy. She said Laura should be committed and "not allowed to have anymore crazy children". Al, with Ziggy's help, warns Sam that Leta is at the Fuller home, tormenting and threating Abigail, trying to get a murder confession out of her, as she then sets the home ablaze. It's now Sam's mission to save and rescue Abigail from the house by breaking an upper hallway window and getting her to jump out of it. Although Abigail escapes, he confronts Leta, but she is able to sneak out of a backroom door as the fire blazes. Ceiling beams afire collapse over Sam just as he leaps.