When an undercover cop in Baltimore involved in a mob investigation goes missing, the BAU believes a serial killer rather than organized crime has something to do with his disappearance. The probe leads to several unsolved missing persons cases.

Elle, along with many others, is held hostage on a train in Texas by a paranoid schizophrenic who is convinced that the U.S. government is monitoring him. Hotchner and Gideon are forced to play into the man's fantasy to save the people he has taken hostage.

A serial killer reappears after 20 years of silence and contacts the BAU with the promise he will kill another victim in the next five days.

The BAU works to capture a serial killer who has evaded capture by altering his appearance.

The BAU has reason to believe a series of murders might have been committed by two people working as a team after the victims' families receive DVDs after each crime that includes psychological attacks.

The daughter of high-powered diplomats, Special Agent Emily Prentiss joins the team, and she must convince Gideon and Hotchner she deserves the job based on merit and not on her family connections. The BAU is then called to St. Louis to investigate two serial killers who appear to be competing with each other. By setting a trap based on one killer's profile, the team creates a media event by which to capture the second killer.

The BAU is called to investigate after the bodies of missing people are discovered in a remote region of the Idaho wilderness. The gruesome find also leads the team to determine the unsubs have been hunting humans for sport.

The BAU travels to Portland to assist local authorities in investigating the disappearances of people who are new to the city and have no strong social ties.

The new sheriff in Fredericksburg, Virginia, requests the BAU's assistance in the investigation of a series of mutilation murders that appear to mimic similar crimes that had occurred over two decades earlier.

The team members try to identify a stalker before he can attack a woman who is being stalked in Silver Spring, Maryland. Meanwhile, Hotch and Rossi are called as consultants on a possible battered woman syndrome murder case in Boston.

The BAU joins the manhunt to catch a serial killer who conceals the manner of his crimes by staging car accidents.

The BAU team suspects a member of an affluent community in Atlanta is responsible for the disappearance of a local young woman and that the suspect may have worked with an accomplice

When profiling a series of child abductions and murders, the team discovers that one of the cases may not be the handiwork of the serial killer they apprehended.