Sleepwalker by Sarah Stegall Copyright © 1994 by Sarah Stegall Writer: Chris Carter Director: David Nutter Maybe it’s too early to worry about the future of “The X- Files”, but I like to get an early start on these things. Glen Morgan and Jim Wong, the best writers for this show, are leaving in January to start their own series, and Ten Thirteen Productions is going to need new blood very quickly. It’s beginning to show. Friday night’s episode, “Firewalker”, was “Alien” meets “Ice” (which was “The Thing”, anyway) meets “Darkness Falls“. Agents Mulder and Scully find themselves involuntarily quarantined,…