It’s been 13 years since Mulder and Scully were on the small screen and eight years since the last ‘X-Files’ movie, so some things are bound to have changed. The new series, which airs on Fox next month, will pick up where 2008’s I Want To Believe left off, but sadly something has happened between the two FBI agents.

David DuchovnyDavid Duchovny is returning to ‘The X-Files’ as FBI agent Fox Mulder.

Speaking to The Hollywood Reporter, star David Duchovny revealed that Mulder and Scully split up at some point between the second film and the revival's first hour. "We're not bickering while we're running with our guns out," Duchovny said.

"The relationship was never played [before this]. It was never ... the predominant aspect of the show as written. It was something that was unspoken. I think it remains that way. I personally don't want to Mulder and Scully sitting in couples' therapy; that's not what the show is. You can find that on other shows.”

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The series will see Mulder once again brought back into the FBI world and although a lot of time has passed, some things still haven't changed. "I've always said, he's the worst FBI agent of all time," Duchovny joked.

"He's never solved a case. He's a bad FBI agent, because he tries to solve cases, but he doesn't try to solve cases where they're prosecutable. Or he's not interested in cases which are going to end up with someone going to jail, or the bad guy being apprehended. He's interested in wonder.”

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The actor also revealed that he’d be willing to return again to the series, but first he wants to see how the new miniseries turns out. "My sense is they're really good, but I haven't seen [them all]," he said. "[And] Chris (Carter, writer) says it depends on David and Gillian. David says it depends on Chris and Gillian. Gillian says it depends on Chris and David. That's where we're at.”

However Duchovny would prefer a smaller number of episodes, like the new Fox miniseries, rather than a full series once again. "Thirteen [episodes] is a little much," Duchovny added. "It would have to be the kind of thing where Chris would come to me and say, 'I have this great vision for 12 or 10 or eight or six.' It's not the number, it's whether or not the number services the story.” ‘The X-Files’ premieres Sunday, January 24, 2016 on Fox.