Which episode introduces Cassandra Spender?

Which episode introduces Cassandra Spender? “Patient X” introduces Cassandra Spender, played by Veronica Cartwright. The episode is the thirteenth installment of The X-Files’ fifth season and first aired on March 1, 1998.

Cassandra is presented as a woman who claims to have been repeatedly abducted by aliens. She wants to deliver what she believes is a positive message about extraterrestrial contact, but her story becomes entangled with a violent conflict involving rebel aliens, former abductees, and the Syndicate. Her arrival shifts the mythology arc toward a larger conspiracy involving alien colonization.

“Patient X” also introduces Jeffrey Spender, Cassandra’s son, played by Chris Owens. The episode is the first half of a two-part story that concludes with “The Red and the Black.” It is sometimes confused with “One Son” or “Two Fathers,” which develop the Spender family and Syndicate storyline further, but Cassandra’s canonical debut is “Patient X.”