The FBI becomes involved in the stalking of a popular singer after she is threatened by an intruder in her house and reveals a series of threatening letters she's received through the mail. Charlie determines the letters are from two different people after analyzing the handwriting. When a photographer is found dead near the singer's house, Don believes the photographer was murdered and his death is somehow related to the stalking case.

Megan feels responsible for an agent's death following an explosion at a meth house the FBI had targeted for a bust. When the kingpin eludes capture, it's discovered he may also be involved in child pornography when one of the photographs on his computer turns out to be a young girl in a sexually explicit position. The picture sends Charlie on a crusade of his own, as he remembers a girl he knew as a young child that he suspected was being abused, and he's determined to save the little girl in the picture.

When an Asian teenager is found in the basement of an old downtown hotel where she was apparently being tortured, the investigation soon reveals the girl and three other missing women, are victims of a black market organ-harvesting scheme. Amita assists the FBI by communicating with the girl, who is from the same part of India where Amita's family once lived.

Don investigates the murders of two young women found in their cars outside their homes. Their deaths were made to look like drug overdoses, but Don realizes a serial killer is responsible. Meanwhile, Charlie is having bizarre dreams about his parents. In one dream, his deceased mother appears and tells him he has a question to ask her, but he can't imagine what it could be.

Don has a problem. Crystal Hoyle and her boyfriend Buck are going on a robbery and killing spree. Their terror is spread over seven states, and Charlie is called in to help. However, problems between Alan and Charlie may hinder Charlie's concentration.

Don and the team investigate a suspicious death at a horse track. When Charlie starts looking into the crime, he uncovers something that will send the investigation into an entirely different direction.

When a former mob hit man on death row suddenly has a change of heart and agrees to confess to his crimes, Don has an uneasy feeling about the whole affair.

In the midst of investigating a serious bomb threat, Don and Charlie uncover a secret that could change their lives and the lives of the team forever.

The team investigates the theft of a graphic comic book.

Don and the team bust a meth lab, but when Don has a feeling there's more to the organization than just what's on the surface, his intuition is put to the test.

In the season finale, Don and Charlie work together on a case that ends up with them going head to head about their personal beliefs, and one team member will walk away forever.

Don and the team investigate when a magician mysteriously vanishes during an illusion.