X-Files fans may never get closure from the show but they'll at least get some answers in a second movie. EW has learned that David Duchovny and Gillian Anderson are both on board. Plus, ''we've worked out most of the plot,'' says X-Files exec producer Frank Spotnitz, who checked in to promote the DVD of his canceled series, Night Stalker. (''People never got to see one of the best episodes we did!'') The sequel will be light on mythology ''It's very liberating to be freed of that,'' he says and picks up four years after the 2002 TV finale that left Mulder and Scully on the run from the FBI. The only hurdle before filming can start: X-Files creator Chris Carter and 20th Century Fox have to settle their suit over syndication profits.