6 things we know will happen on Fox's 'X-Files' return

About 13 years after "The X-Files" went off the air, the series is back on Fox.

It reunites agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) for an adventure that promises to both honor the shows roots and redefine them. 

"It's a re-entry into a series that hasn't been on the air for 13 years. I think you needed to get back into the characters' lives, their quest, where they are, where their relationship is and where their professional lives are," Carter said of the series return.

The show will have to do all that in just six episodes, which will consist of two "mythology" episodes, which are part of the show's through-line story, and four "one-off" episodes that could stand alone.

"The signature of the show was that we would do a mythology episode, then you could do a monster-of-the-week episode and go right back to the mythology episode and it worked," Carter said. "In this case, there are only six episodes so we had to do it in a shorter arc."

Although there's a lot of questions to be answered on "The X-Files," we do know something about what's coming up.

Here are six things we know about the upcoming "X-Files" return:

(Needless to say, there are spoilers for ahead.)