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.
A new case has similarities to a past case and a serial killer Megan helped send to prison.
Kate begins to suspect that the handsome and mysterious Sergei, with whom she's having a tryst, may be involved in the death of a young Russian girl.
Megan and Tommy attend her father's exhumation but it only yields more questions. Joan suggests Megan check out her father's patient files for a connection to his death.
When Tommy is discovered at the scene of a young girl's murder, covered in blood, Megan is his only hope.
The team needs to quickly figure out how to treat the virus when more and more people are becoming ill and dying.
The team must make sense of the unknown drugs in a 17-year old high school student after he's discovered dead following a rave. Just when Megan is starting to get on with life after divorce, Todd gives Megan and Lacey some staggering news.
When a pharmaceutical rep is murdered, Megan and the team must find the original crime scene if they hope to find out the cause of death and why the body was drained of blood. A big hurdle to overcome is the number of suspects with access to lots of unknown drugs.moreless
An undercover cop is discovered murdered at a truck stop.
A case of mistaken identity mars a case when two young girls are in a tragic car accident. The wrong girl may have been pronounced dead and the actual cause of death is in question.
When an expert horsewoman who ran a vocational program is murdered, the lead suspect is a woman in prison on drug charges. Todd doesn't react kindly when Megan takes Lacey to the crime scene, but the same can be said for Megan when Todd decides to take Lacey along on vacation with his new girlfriend.moreless
An investment banker on trial for defrauding investors is kidnapped leaving court and later surfaces in a video as having been killed. Tommy and Adam have to determine if he faked his own death. Megan learns more about her father.
A woman's savage murder leads Megan and Tommy to a neighbor inflicted with rabies who bites Tommy and is diagnosed with rabies. Kate calls in the new health commissioner, Dr. Charles Stafford, to help Megan when a second case of rabies is discovered sans bite marks.
A wedding turns into a crime scene after the bride falls to her death and everyone including her father is a suspect. Ethan is captivated by Dani but she's already found another love interest.
Everyone becomes a suspect when a lottery winner is viciously murdered.
A child is missing after his nanny is the victim of a hit and run. Megan investigates the death alongside an FBI agent assigned to the case. A misstep in the interrogation of the prime suspect places Bud under critical inspection. But when Joan offers her help, Megan is suspicious it's just a PR stunt.moreless
Dr. Hunt and the team examine a family restaurant business when the owner turns up dead in the freezer.
A dead body found in the trunk of a car leads the team to another body. Megan meets up with an old friend and Kate feels her job is in jeopardy.
When a son discovers his murdered parents, the team soon realizes that this perfect family wasn't really perfect. Megan has a new love interest and Curtis is grappling with his new position.
Megan and Tommy must determine who killed a schizophrenic teenage girl at a mental institution. To make things interesting, a patient claims that the murderer really meant to kill her, and they are being stymied by the ward director.
Working with Tommy on a vigilante killing, Megan meets up with a grief counselor who offers to help her deal with issues about her father's suicide.
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.moreless
The shooting death of a New York mobster's son creates a tense situation when the mobster threatens to find and kill the person responsible. Megan and the team must hurry to solve the case after one suspect is killed.
A new investigation is opened up after a man assumed to be dead disappears off Ethan's exam table. When another body is found, it's the DNA evidence that leads to an eye-opening discovery.
A medical student is Megan's key to figuring out how the body of a murdered woman turned up in place of a cadaver at a medical school.
A middle-aged man is killed after his car goes out of control and over an embankment. Although the neighborhood seems idyllic, Megan finds that things are not as they seem and the list of suspects keeps changing.
Kate removes Megan from a murder investigation involving a deer hunting party when Megan openly accuses a wealthy and influential tycoon of shooting his young wife. Kate's actions make for an even chillier relationship between the two women. Megan is then assigned the case of a man who's been repeatedly beaten by a heavy object which only leads Megan back to the first murder.moreless
A plane crash in Philadelphia takes out the city's main power grid making it difficult for Megan and the rest of the team to conduct the necessary autopsies. While investigating the plane crash, Tommy and Riley are involved in a serious car accident.
While Kate comes under fire from D.A. Russell, Megan has cracked the case but can't tell her team. As long as the killer has Lacey, Megan must keep what she's learned to herself.
An accused murder violently escapes from a transport van and soon the witness in his case is found dead. He heads straight to Megan pleading that he's being framed and didn't commit the murder. It's up to Megan to find the truth.
As Megan returns to work months after Peter's death, she is thrown together on a new case with a detective from her past. A serial killer is seeking out young war veterans but the case hits close to home for Megan when the killer takes Lacey hostage.
Megan and Tommy must separate out fact from fiction to determine if a child's murder was severe child abuse or something else.