, titled " Ghouli ," originally aired on January 31, 2018. Written and directed by James Wong, the episode begins as a "Monster-of-the-Week" mystery but quickly shifts into a critical installment of the series' overarching mythology. Episode Summary
The plot follows two teenage girls who attack each other on a derelict ferry, each believing the other is a terrifying monster known as a "Ghouli". Mulder and Scully’s investigation reveals that both girls were dating the same boy, Jackson Van De Kamp. Scully soon realizes that Jackson is her long-lost son, , whom she gave up for adoption years earlier. Key Plot Points & Revelations The X-Files recap: 'Ghouli' - Entertainment Weekly The X-Files 11x5