This is, in my opinion, the best episode of the season and one of the best of the entire series. The plot is original and has so many twists and false endings.
For people who think that by season 6 the standalone episodes of this show are getting a little formulaic, this should prove conclusively that is not the case.
Just a few of the many memorable moments are when Skinner gets shot by Mulder, Mulder abducts an alien and Scully admits that Mulder has been correct about every conspiracy theory he supports.
This is an absolute must-see for all fans of this show, and if you aren't a fan of the show this just may get you hooked, so watch with caution! ;)