The BAU team investigates a mass murder at an Internet security company in Charlottesville, Va., but clues reveal it is not a typical serial killer at work. Also, Prentiss must complete recertification training under Morgan's watchful eye.
Deep Throat tips Mulder to a critically important case involving a missing fugitive and the cloning of extraterrestrial viruses.
Kate's original crime that started her life on the run is revealed. Meanwhile, the survivors lay one of their own to rest, Kate sleeplessly watches over a feverish Sawyer, and Mr. Eko has a surprise for Locke regarding the hatch.
During a simulated battle, Reese's team of soldiers ends up getting captured because Reese has trained himself not to think; and in court, the evidence against Hal continues to mount.
While investigating a rural religious cult, the agents expose a sinister experiment involving violent teens and alien DNA.