The episode opens with an introduction by the Cigarette Smoking Man (William B. Davis), in which his full name is revealed as Carl Gerhard Busch.
Dana Scully (Gillian Anderson) wakes up in the hospital after having a seizure, now realizing the apparent invasion was a vision and hasn't actually happened yet.
Mulder initially presumes Scully's ramblings are a product of her illness, but leaves the hospital to investigate.
Spender hides behind a door of an apartment building as his would-be assailant demands the whereabouts of a boy.
He first balks at telling her the location of her son, revealing only the name of the family that adopted him – Van De Kamp.
Mulder tails a henchman who he believes will take him to the Smoking Man, but he arrives somewhere else with mysterious conspirators; Mr. Y (A.C. Peterson) and Erika Price (Barbara Hershey).
The episode is notorious for completely changing a respective part of the show's mythology: revealing that Mulder is not William's father, but that Cigarette Smoking Man had drugged and raped ("artificially impregnated") Scully years ago.
This also answers a respective scene from season 7 episode "En Ami" in which Scully woke up in a room in pajamas during a road trip with the Cigarette Smoking Man, accusing him of drugging her.
"[2] Besides main cast members David Duchovny, Gillian Anderson and Mitch Pileggi, the episode features several guest stars, including original series stars William B. Davis and Annabeth Gish, and the return of Lauren Ambrose and Robbie Amell, whose characters debuted in season ten.
[4] The episode received strong backlash from fans, particularly the reveal that Cigarette Smoking Man was the father of Scully's son William.