Valens helps Rush to find her abducted, drug-addicted sister while Jeffries follows a new clue in an attempt to bring closure to a case that has been unsolved for 17 years.
The team investigates the 1989 case of a prom queen, killed by a hit-and-run after her prom. Rush's sister, Christina, suddenly resurfaces but Lilly has her suspicions.
In the conclusion of the two-part episode, the Philadelphia PD and the FBI continue their joint operation to catch the serial killer before he strikes again.
In the first part of a two-part episode, the team begin a joint investigation with the FBI regarding a serial killer who has re-appeared after 27 years of silence.
When new evidence of potential foul play emerges, the team re-opens the 1971 case of a teenage circus aerialist who fell to her death while performing a dangerous new act.
The team re-investigates the 2005 murder of a Green Beret recruiter who was suspected of being a jewelry thief when his former subordinate presents compelling evidence for his innocence.
The team re-investigates Lt. Stillman's cold case from 1983, the death of a Chinese-American teen whose girlfriend had been killed by Chinese gang members only three months earlier.