The rings of blood around the graves are described as ouroboros. Scully gets a tattoo of this symbol in Never Again (1997).
With Lance Henriksen reprising his role as F.B.I. Agent Frank Black, this episode acted as a series finale for Millennium (1996) as it had been canceled with unresolved plot threads.
Plans for a proper crossover were discussed when Millennium (1996) was still airing. It was only with the cancellation of the show that Chris Carter started seriously thinking about how to close off Frank Black's story.
Plans for a proper crossover were discussed when Millennium (1996) was still airing. It was only with the cancellation of the show that Chris Carter started seriously thinking about how to close off Frank Black's story.
The idea for the episode sprang for an aborted pitch to do a zombie X-File with George A. Romero directing.