"Exodus"
Working Airdate: November 7, 1999

8.20.99:

From "The Wire," borrowed from The Haven

THE X-FILES' seventh season begins with a two-episode story
        arc (finishing Sunday, Nov. 14) that concludes last season's
        finale as it brings Agent Fox Mulder (David Duchovny) to the
        brink of death and Agent Dana Scully (Gillian Anderson) to
        what may be the source of a life on Earth -- a source that
        appears undeniably alien.

        The season opener finds Mulder locked away in a mental
        institution, his physical and mental health rapidly deteriorating
        while Scully frantically tries to discover the cause of his illness.
        While Scully's quest takes her to a faraway continent, where
        she is forced to confront the seeming reality of alien life,
        Mulder turns for help to Assistant Director Walter Skinner
        (Mitch Pileggi), who reluctantly agrees to sacrifice Mulder's life
        for the sake of proving the alien origin of his illness.

        The first two episodes also feature a return appearance by
        Mimi Rogers as Agent Diana Fowley.
 

6.1.99:

These spoilers/rumors I snatched from the wonderful website of Kelli Rocherolle.  I am not sure of her source, however:

Episode:  7X01 (Part 2 of 2)
Working title:  "Exodus" [Rumored!]
Title Meaning:  Greek for "departure"
Genre: Mythology,  Season Premiere
Tentative Airdate:  11/07/99
Writer:  Chris Carter [and Frank Spotnitz]
Director:  Rob Bowman or Kim Manners
Cast:  Gillian Anderson as Sp. Agt. Dana Scully,
David Duchovny as Sp. Agt. Fox Mulder,
Nick Lea as Alex "Ratboy" Krycek,
Mitch Pileggi as AD Walter Skinner,
William B. Davis as CSM, [...]