S8, E15: Shortly after Mulder is buried, Billy Miles is found dead, but somehow comes back to life. Skinner and Scully put all their hopes into digging up Mulder and discover that he too, is still alive. As Mulder lies in hospital without indication that he will fully recover, Krycek comes to Skinner and offers him a vaccine to the virus that has infected Mulder, but at a terrible cost.