1x15 - Watch X-files

: Mulder's theory is bolstered by subtle changes: the previously right-handed Willis begins using his left hand (Dupre's dominant hand), forgets Scully’s birthday (which he normally shares), and develops a sudden tattoo that mimics Dupre's.

: At the hospital, Willis flatlines for several minutes while Dupre is simultaneously declared dead. Just as Dupre's life ends, Willis is miraculously revived, leading Mulder to suspect that Dupre's consciousness has possessed Willis's body. Watch X-Files 1x15

: The episode ends tragically as Willis (under Dupre's control) dies of a diabetic coma after consuming too much sugar, unaware of Willis's medical condition. Episode Details Original Air Date : February 4, 1994. Directed by : David Nutter . Written by : Howard Gordon and Alex Gansa. : Mulder's theory is bolstered by subtle changes: