A janitor takes Clark's high-school class hostage at LuthorCorp., claiming his "jitters" were caused by a mysterious contaminant.
A test pilot who may have been flying aircraft made with alien technology disappears, and Mulder and Scully must defy their own government to find the truth.
During the murder investigation of three identical doctors Mulder makes a stunning discovery regarding his missing sister and Scully's life is threatened by a shape-shifting bounty hunter.
While tracking the ruthless bounty hunter who has abducted Scully, Mulder uncovers an alien plan to colonize Earth.
Following the death of his gangster son in a police shootout, mobster Tommy Colette vows to kill Tony Scali himself.