IF there’s a recipe for reviving characters last seen on the small screen 13 years ago, it’s one that needs bucket loads of chemistry.

Enter Gillian Anderson and David Duchovny. When they revive cult classic roles of Scully and Mulder this week in The X-Files it will be an attempt to reboot a partnership that captivated a generation.

Anderson says the chemistry she and Duchovny have is “beyond” them.

“David and I have that chemistry whether we are just talking to each other, having that — just in ourselves, not even in these characters it exists, and it is beyond both of us,” she says.

The actors are close friends and have played on the relationship to promote the show’s revival, littering their social media accounts with flirtatious selfies and witty repartee.

Duchovny says he became emotional when he first saw the script for new six episode series.

“It was nostalgia. Just to see Mulder and Scully on the page and all that stuff,” he says.

“It’s like reading a letter from camp that you wrote when you were 15.”

At its peak in the ‘90s, The X-Files was part of the cultural zeitgeist — dominating ratings and carving out the role of ‘appointment TV’ in modern lives. The advent of streaming and instant TV means the show has a whole new landscape to contest.

When they return to the small screen, Mulder and Scully are no longer a couple. Mulder has become reclusive, and Scully works as a surgical assistant in a hospital with children.

Duchovny says slipping back into character was difficult at first.

“I think at first, it was a little rusty and a little tense. Because none of us really knew what to expect, how it would feel. But then, it just took maybe half a day to kind of fall into a rhythm,” he says.

“I think it’s like being a band. It’s like playing music with somebody you’re used to playing with.”

When The X-Files went off air in 2002, it was the beginning of a post-9/11 era that had no interest in government conspiracy, says creator Chris Carter.

Carter believes that although the themes had run their course at the time, they are again as relevant as they ever were and he sees X-Files storylines everywhere.

“Every time I pick up the newspaper now I see an X-Files story…When the call came in I immediately saw the possibilities and beauty of doing a number of stories rather than just one big story.”

The new series will deal with modern issues, including one episode that tackles terrorism.

“I think that is more relevant today certainly after the attacks in Paris and now here in San Bernardino than it might have been even before we were filming the episode,” he said.

Carter and his team had campaigned unsuccessfully for years to bring the band back together for a movie before the idea of a limited run TV show dawned on them.

They all hint that there could be more episodes on the table if the mini-series is successful.

“It’s always open…to me, it’s always open,” says Duchovny.