Kathryn Morris stars as Philadelphia homicide detective Lilly Rush, who investigates long-unsolved crimes, otherwise known as Cold Cases. In the pilot episode, Lilly investigates a 1976 case involving a teenage girl who was beaten to death on a tennis court during a party at a plush estate. A maid to a wealthy family, Bonita Rafaela (Lillian Hurst), claims she witnessed the murder of teenager Jill Shelby (Kate Mara). Now dying of cancer, the maid who remained silent, wants the killer brought to justice. Rush reopens the case, in which two brothers were originally suspected but not charged due to their powerful society family.