Megan comes face-to-face with a convicted serial killer she helped put away.

Megan's father's exhumation uncovers more questions about what she always believed was a suicide, and her mother suggests she examine his patient files for clues about his death and that of a patient.

When a city-wide outbreak of a mysterious and lethal virus occurs, even Megan and her team are at risk. In order to determine who and what caused this outbreak, CDC Officer Charlie Stafford takes over the investigation.

The team needs to quickly figure out how to treat the virus when more and more people are becoming ill and dying.

A murdered young woman's body turns up in place of a medical school cadaver during class, leaving Megan to rely on the aid of the star student to help solve the case.

After Peter rescues a woman from a house fire, Megan discovers another person in the house who died. Peter takes the discovery personally since he had no idea anyone else was in the house. A veteran arson investigator challenges Megan at each step in her investigation. When Megan complains to Kate the response she gets only intensifies the tension between the two women.

A schizophrenic teenage girl at a mental institution is found murdered. When Megan and Tommy interview a young patient named Darby, who seems extremely sane and lucid, she tells them that she saw the killer climb down from a heating vent in the ceiling, but most shocking of all -- he meant to kill her, not the actual victim. Could the killer be Dr. Malcolm, the ward director, who is obstructing their investigation.

Kate becomes involved with a man she met at a political event, but when a young Russian girl is found dead, she suspects that he may have something to do with the murder, and looks to Megan for help.

When two young girls are in a tragic car accident, one is left in critical condition and the other is found dead at the scene. As Megan and her team investigate the case, however, they realize there has been an awful mistake. Not only was the wrong girl pronounced dead, but the car accident may not have been the actual cause of death.

When a severed hand and foot turn up in a back alley, Megan and her team must literally piece the victim back together. Meanwhile, Megan's daughter, Lacey, gets her mother's reluctant permission to visit her at the office and film her at work as part of a video essay for Social Studies class. What Lacey learns in the process profoundly changes her view of her mother

When a young girl is found murdered, Megan has to put her personal doubt aside and help a blacked out Tommy, covered in blood, prove his innocence.

When a woman suspected of murdering her son is found innocent, Megan and the team try to identify the real killer; an overzealous reporter makes the investigation difficult by sensationalizing the case.

An undercover cop is discovered murdered at a truck stop.

The investigation into a fatal car crash reveals the seedy underbelly of a perfect-looking neighborhood.

Part 1 of 2. In the Season 3 premiere, it's months after Peter's death and Megan returns to work, only to learn she's been teamed with a detective with whom she has a past history. She, Det. Sullivan and his rookie partner are up against a serial killer who targets young war veterans. The stakes become higher after she gets a call from the killer and is told he's holding her teenage daughter, Lacey, hostage.

After a car accident reveals a dead body in the trunk, the team is led to another body, giving the team two cases to solve; Megan is reconnected with an old acquaintance; Kate's job is threatened.

When a young, interracial couple is found shot and killed inside their car in Fairmont Park, Dr. Megan Hunt promises the grieving parents that their daughter’s killer will be found. Detectives Bud Morris and Samantha Baker are ready to chalk the case up to a murder-suicide, but Megan and her team find evidence on the bodies that sends the case in an entirely different and shocking direction. Meanwhile, Peter advises Megan not to push too hard when it comes to reconnecting with her daughter, Lacey.

An inmate violently escapes from a prison transport van and becomes a dangerous fugitive on the run in Philadelphia. Soon another man turns up dead - who's revealed to be a witness in the escaped prisoner's murder trial. Megan must continue to search for the truth in the original case when the accused murderer shows up and pleads with her that he is innocent and being framed.

When a recent lottery winner is found brutally murdered, everyone becomes a suspect.

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.

Many suspects emerge after a rich tycoon's new, young wife is shot during a deer hunt; Kate and Megan's relationship takes a turn for the worse.

A magazine editor is found dead in her mansion; Megan confronts a suspect while at a social event with her mother; Ethan surprises Kate with his positive attitude.

Megan and Tommy investigate a murder that appears on the surface to be a case of severe child abuse. But the girl's parents claim that their daughter was killed by the Devil after being possessed. The team must try to separate fact from fiction when the victim's mother begs Megan to help her stop the same thing from happening to their surviving daughter.

Megan is surprised to discover she has a connection to a woman found dead in a hotel room; Megan starts taking an interest in what is going on around her.

After a murder suspect escapes from a prison-transport van, a witness in his trial turns up dead, and while Megan is investigating, the fugitive makes contact and tries to convince her that he's innocent and being framed.

In conclusion of the two-part Season 3 premiere, Megan discovers why the serial killer targeted war veterans, but must keep the information to herself or risk the life of her daughter, who is being held hostage by the assassin. Meanwhile, District Attorney Dan Russell has a run-in with Kate.