After being gone for almost a year following her abduction, Cassandra Spender reappears, in perfect physical condition as the first successful alien/human hybrid. The consortium scrambles as the faceless alien rebels seek to expose their conspiracy with the colonizing aliens. Mulder and Scully try to discover the identity of the Cigarette Smoking Man and protect Cassandra from the consortium who want her dead. Written by
Did You Know?
We learn the name of the black oil virus: "Purity". See more
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. See more
[referring to his and Scully's discovery of the Smoking Man's identity in the FBI's database
Smokey's got a name.