When a young woman, Rosie, wakes up from a coma, Lilly re-opens the fall in which her 6-year-old daughter Toya died.

Things get complicated when the mother remembers very little of that night, and Lilly feels especially motivated to find the killer.

Construction workers discover a skull with bullet hole under the ruins of a disco club burned down in 1978. 22 people died in the fire. Rush and Valens come to the conclusion that the burning of the club was arson, meant to cover up a murder leaving them with not one, but 23 cold cases.

The team re-opens the 2000 case of a prominent Puerto Rican assistant district attorney when rumors about his connection to a large amount of money gone missing at the time of his death start to circulate. However, his widow insists that the claims are not true. The re-investigation reveals that the victim was prosecuting a murder trial and the man convicted for the crime after his death may possibly be innocent.

When a dying boxing referee makes a confession about a 1976 fight, the team re-opens the case in which an underdog fighter, arranged to fight against a much more qualified boxer, took a heavy beating in the match and died only moments afterwards.

A woman, who was romantically involved with Nick Vera in high school, claims that members of a fraternity might have been involved in her alcoholic sister's death in 1995. The victim's estranged husband and a bar owner are also viewed as potential suspects.

Lilly re-opens the 1999 case of a young, healthy woman who nevertheless died of a heart attack. In the late 1990's, she was briefly an Internet millionaire, but due to bad business decisions, her dot.com company eventually went bust.