When Deep Throat points out a news story about a fugitive who apparently drowned, Mulder and Scully cannot see what makes the case special but follow it up anyway. With Deep Throat's insistence, they discover evidence of a secret government project code-named Purity Control, which uses human test subjects and infects them with extraterrestrial DNA. However, the evidence and everyone who has seen it is quickly being eliminated.
Elenco: Gillian Anderson , David Duchovny , Mitch Pileggi , William B. Davis , Annabeth Gish , Bruce Harwood , Cary Elwes , Dean Haglund , James Pickens Jr. , Nicholas Lea , Tom Braidwood , William B. Davis .