Sammy and his pals Ollie and Burgy like snooping around Mrs. Armbrose’s decrepit old barn. They disobey her and wander deep down into an abandoned root cellar. Nothing looks unusual until Sammy discovers what looks like a jar of preserves. It’s not until he tastes its lime-green contents that he is plunged into the near past and begins a terrifying adventure. It takes Sammy several short trips back to realize that by reliving his own history he can remove all of his mistakes, blunders, and embarrassments that made him unpopular. But the chilling truth is that with each time trip he also disrupts the delicate balance of time and space to set up the destruction of the universe!