PPD had decided a serial bomber had died or moved on when 5 years passed with no bomb fatalities in Philadelphia, but a pilot was seriously injured in a sports club by a bomb with identical characteristics. He tells Lilly he had heard music just before the bomb went off; a janitor reveals he had seen a music box in the locker which exploded. The Cold Case team realizes they need to find a link among the seemingly unconnected victims.
A drug bust discovers that an ex-convict had been murdered soon after being released in 1997. The investigation discovers that he had been attempting to reestablish a relationship with his teenage son, who had been five years old when he went to prison, against the wishes of the boy's mother and stepfather. The detectives also learn that a former associate had been attempting to lure him back into the life of crime.
In 1962, a woman's death is ruled a suicide. Her granddaughter asks the team to investigate her suicide after she provides them with newer evidence she hopes will prove that her grandmother's suicide was actually a murder.
Remains found in an oil drum at the Philadelphia are identified, by dog tags, as belonging to Jimmy Tully, a Marine who went AWOL while on leave in 1951, opening up a murder case for the first time. Among the witnesses and suspects are members of his unit, his sergeant, a beautiful girl and a jealous guy from a Navy bar that the victim visited while on leave. As usual, all of these people are still alive and in Philadelphia. In the end, the murderer confesses and Tully's family can be proud of him, finally.
A fan of a 50s pin up girl comes forward with a new lead in the shooting death of the girl. A photo revealing the killer may not have been a random break in as believed. Could it have been her photographer, manager, best friend or stalker?