En tenåringsjente blir myrdet på et mentalsykehus, og Megan og Tommy intervjuer en pasient som mener at hun var det tiltenkte offeret, og ikke jenta som ble drept.
En passasjer starter en skuddveksling i et passasjerfly, som ender opp med å krasje i Philadelphia. Hele teamet trår til for å hjelpe, og når Megan foretar obduksjoner mellom strømbruddene forsvinner et av ofrene.
Etter at en drapstiltalt mann flykter fra fangetransporten blir et vitne i saken hans drept. Mens Megan etterforsker saken, tar den drapsmistenkte kontakt og hevder han er uskyldig.
Megan lurer på om faren hennes virkelig begikk selvmord, og moren foreslår at hun undersøker de medisinske dokumentene hans for å finne ut mer om hvordan han døde.
Months after Peter's death, Megan returns to work and is surprised when a man from her past is assigned to her case; a serial killer targeting young war veterans takes Lacey hostage.
Megan cracks the serial killer case but can't reveal the answers to her team while Lacey's life is in danger; District Attorney Dan Russell targets Kate.
Megan and Tommy are faced with an unusual investigation when a couple claim their daughter was killed by the devil.
After his son is gunned down, a New York City mob boss threatens revenge, and when an early suspect is found dead, Megan and her team begin to believe the carnage has just begun.
Megan and Tommy investigate two murders that seem to be the work of a vigilante; Megan takes up an offer of counseling, from a victim's father.
Kate falls for a handsome and mysterious man named Sergei at a political event; when a girl is murdered near the hotel where Kate and Sergei are staying, Kate thinks Sergei may be responsible.
During a murder investigation, a woman bites Tommy; Megan turns to the new health commissioner for help uncovering the truth behind strange rabies cases.
Megan arrives at the scene of a young girl's murder and finds Tommy covered in blood; as evidence piles up against Tommy, Megan tries to ignore her doubts and prove his innocence.
A wealthy fund manager accused of defrauding investors is kidnapped; Megan gets closer to discovering the truth about her dad.