The return of an alien abductee threatens to finally expose the conspiracy involving extraterrestrials, forcing the Cigarette Smoking Man to strike back at Mulder and Scully with greater determination.

original airdate--February 7,1999                           rating--18.81  million

music--theme song "X-Files" by Mark Snow"

Goofs: The special effects operator and his fire rig are briefly visibly when the rebel alien kills the Syndicate elder while disguised as Dr. Openshaw.

• In every other episode, the ice pick to the nape of an alien's neck releases toxic fumes, along with the ichor, but in this episode, when Agent Spender and Krycek kill the rebel alien, they are unaffected by the exposure of the ichor to air, which should have been toxic for them to inhale.

Trivia:We learn the name of the black oil virus: "Purity".

• The Cigarette-Smoking Man's "real" name, CGB Spender, is used for the first time.