First telecast February 13, 2000, "Closure" is the conclusion of a two-part X-Files story that began with the previous week's "Sein und Zeit." Investigating the disappearance of little Amber Lynn LaPierre (Megan Corletto), Mulder and Scully capture a serial killer who admits to having murdered 24 children -- but not to the murder of the girl in question. Meanwhile, Mulder falls under the influence of a psychic who sees a connection between Amber's disappearance and the still-unsolved abduction of Mulder's own sister. As Scully worries about Mulder's fragile mental state, the story reaches a climax that fueled many a water-cooler conversation the day after the episode originally aired. The aptly titled "Closure" was written by series producers Chris Carter and Frank Spotnitz.
by Hal Erickson synopsis