Alex Krycek
From the second season onwards, he served as one of the show’s secondary antagonists to main character Fox Mulder, with whom he shared a complicated relationship. He was varyingly seen as either a henchmen or enemy of the show’s main antagonist, Cigarette-Smoking Man.
The Blessing Way
Scully finds her career with the FBI in jeopardy as Mulder is still missing and The Cigarette Smoking Man is pursuing the stolen files. The Navajo elders find Mulder’s body in a cave and perform an ancient ceremony to call the spirit back to the empty vessel.