I you liked the TV series, you're going to love this!

The X-Files' plot more or less works. The movie starts out in a dark cave around 600 A.D. where cave men are attacked in this cave by a scary looking alien creature, when it is killed it leaves behind an oily substance that digs into the body of one of the men. Then we warp to the present where a boy falls into that same cave, and gets infected with that same substance. When a federal building in Dallas in blown to ashes, Mulder and Scully try to track down who did this a for what purpose.
The X-Files movie is terrific film crafting, combined with very good special effects and an interesting plot. I've been a X-Files fan since season three, and I went to see this movie the first week it opened. I was glad I did, for it was excellent. It picked up right where the season finale ended, with the x-files currently shut down, and Mulder and Scully re-assigned to other areas.
There are some familiar characters in the movie like smoking man (William B. Davis) and Well manicured man (John Neville). I would recommend "The X-Files" to fans of the series, and maybe to people who haven't yet seen the series and want advise whether or not to see this film, I would give a big yes!