After a robbery gone wrong ends with a murder and kidnapping, the team races to rescue a mother and daughter whose abductors are not what they seem. Also, Crosby enters a new living arrangement.

After a double murder takes place in a small town, the team goes after the vigilante who relies on internet sleuths to exact revenge on suspects in the name of justice. Also, Jess and Sarah's relationship continues to grow, but not everyone approves.

After a deadly fire at an arcade, the team discovers the blaze was just the first step in an intricate plan to exact revenge on one of the victims. Also, Hana rejoins the team, finding new adjustments in all aspects of her life.

The team gets called to Vermont after a married couple who grow illegal marijuana massacres their employees. Also, Barnes begins to regret not taking any time off to bond with her new baby.

When a celebrity child psychiatrist is kidnapped by the relative of a former client, the team races to track down the perpetrator and learns what really happened to the psychiatrist's client; Kristin confronts her deep-rooted trauma.