David Duchovny FBI Special Agent Fox Mulder Actor Gillian Anderson FBI Special Agent Dana Scully Actor Mitch Pileggi Asst. Dir. Walter Skinner Guest Star Nicholas Lea Alex Krycek Guest Star Jon Gries Salvatore Matola Guest Star Steven Williams Mr. X Guest Star Don Thompson Henry Willig Guest Star David Adams Dr. Francis Girardi Guest Star Michael Puttonen Dr. Pilsson Guest Star Anna Hagan Dr. Charyn Guest Star William B. Davis Smoking Man Guest Star Mitchell Kosterman Det. Horton Guest Star Paul Bittante Team Leader Lt. Reagan Guest Star Claude De Martino Dr. Saul Grissom Guest Star Howard Gordon Writer Rob Bowman Director