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.

When a young nanny is run down by a car and killed, the 5-year-old child she was watching is kidnapped; an interrogation goes awry.

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 champion equestrian is killed and potential drug use is suspected, but when Megan's daughter, who also rides, overhears details of the case, she leads the team to a clue and possibly the murderer.

When a popular 17-year-old high school student is found dead after a rave, the team must decipher various unknown drugs in his system and multiple bruises to figure out the cause of death. Meanwhile, Meghan is finally starting to date again after the divorce, but her ex-husband springs some shocking news on her and her daughter, causing tension at home.