Young Jessica Fletcher's life couldn't be more ordinary. She teaches at the local high school while she and her loving husband, Frank, are raising their nephew Grady together. But when the beloved principal dies under mysterious circumstances, Jessica knows something is off and, for the very first time, investigates a death. Present-day Jessica returns to high school for a colleague's retirement party and has fun seeing familiar faces. That is, until the colleague winds up dead—and his death has mysterious links to Jessica's very first murder case. With nothing but her own instincts to guide her, Jessica embarks on a quest to find out what really happened all those years ago and who's behind these murders. Because time is running out to catch this killer...