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 Jakarta, claims she witnessed the murder of teenager Jill Shelby. 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.

Lilly re-investigates the case of a murdered church organist (John Walcutt), when his Alzheimer's-stricken widow (Isabella Hofmann) begins having flashbacks of the night in question. Lilly's investigation has both Mitchell's son, Ryan (Jimmi Simpson), and daughter, Tina (Daisy McCrackin), demanding Lilly close the search.

When an old truck containing human bones is pulled from the Delaware River, the team re-opens the case of a missing and possibly murdered girl who disappeared unexpectedly in 1932.

When a young girl is contacted by a man claiming to be her father, Det. Rush and her team reopen a 1988 case of a teenaged boy, killed on the same night the girl was born.

Four close high school friends each went their separate ways in 1980. Eight years later, in 1988, one of them was murdered. The homicide team receives a tip about the murder, prompting a re-investigation of the case and an examination of the friends' lives, hopes and dreams after high school.

Lilly investigates a 1995 shooting spree at a mall in which two teen boys killed 15 people before committing suicide. The case is reopened when a video of the crimes is found and it suggests that a third shooter was involved. Elsewhere, Stillman asks Valens to investigate whether Valens' brother may have been molested by a boxing coach in the 1980s.

When a body is found in a dumpster, the team re-opens the 1984 case of a murdered teenage boy who wanted to become a dancer against his father's wishes.