Mulder and Scully head to Ellens Air Force Base to investigate the mysterious case of a military test pilot who disappeared after experiencing strange psychotic behavior. While on the case, Mulder meets a mysterious man dubbed 'Deep Throat' who claims to have classified information about his investigations into the paranormal.

As Section Chief Blevins expresses his concern with the direction of the X-Files, Mulder becomes obsessed with solving a case that closely parallels an encounter he experienced as a child: the abduction of his kid sister, Samantha.

A.D. Skinner sends Mulder to investigate a body which washed into the New Jersey sewer from the ocean. Mulder believes that the basic blue-collar assignment is punishment, but by Skinner's own admission, what he discovers is a true X-File.

Pusher returns as Robert Patrick Modell escapes from the mental hospital and the FBI promptly organizes a manhunt, assuming that he will continue where he left off. But is he really trying to get revenge on Mulder, or does he want to warn him of another evil?

Mulder and Scully have 24 hours to save A.D. Skinner from being killed by a biologically engineered disease. The disease appears to be created by a shadowy government organization, but in order to save Skinner's life they must determine who wants him dead and why. With Skinner's condition worsening, Mulder seeks assistance from Senator Matheson, who he hopes can provide some answers and help him to find a cure.