The conspiracy theory series, The X-Files that followed the investigations of F.B.I. special agents Fox Mulder and Dana Scully are to come back next year, 24th/25th January 2016 to be precise in a mini-series. Those dates are for the U.S. audiences, no details for the rest of the world yet. Whilst that is not news and has been known for a while, what is new is that the trailer for the series has been released. The trailer doesn't give too much detail apart from indicating a story that has a historical story to it. Asst. Dir. Walter Skinner, Fox and Dana's boss at the F.B.I. also makes a return appearance. Although you don't see his face, it is implied that Cigarette Smoking Man is also back having survived the assassination attempt on his life at the end of the series.
In addition to the series, there was a The X-Files, the Movie which was set between series 5 and 6 which featured the Syndicate working alongside alien technology which culminated in a U.F.O. - Unidentified Flying Object taking off from under Antarctica. After the series finished in 2002, there was a second film The X-Files, I Want to Believe in 2008 which focussed more on the supernatural then on Aliens.