The X-Files: Rhys Darby teases his role in 'Mulder and Scully Meet the Were-Monster'

Rhys Darby has suffered for The X-Files.

For starters, there’s the cut the Flight of the Conchords actor and comedian sustained while filming a fight sequence for Monday’s episode. “It required a few stitches,” Darby tells EW of the injury. “But now I’ve got a nice little scar to remind me of The X-Files. The guy stitched it up with a couple of little x’s … It all makes sense.”

And the stitches on his finger might actually pale in comparison to the task of keeping quiet about the nature of his role in Monday’s hour of The X-Files, which EW’s own Darren Franich calls, “a wild, playful, brain-twisting, heart-pulling, and above all adventurous episode of television.” Darby struggles to describe his character without getting into territory that might spoil the viewing experience for fans.

“It’s really difficult, really!” he laughs.

Darby can say this about his character, Guy Mann, whom Mulder suspects is involved in a series of deadly, what-appear-to-be-animal attacks: “Viewers will be surprised. I was surprised. It’s a wonderful twist on the old classic were-monster.”

Written and directed by Darin Morgan, who has taken home an Emmy for an X-Files script once before (season 3’s “Clyde Bruckman’s Final Repose”), the aptly titled “Mulder and Scully Meet the Were-Monster” is an hour that Darby is confident will be “satisfying for an X-Files fan. It’s the ultimate episode. And it’s funny, which is the icing on the cake for me.”

The episode also honors the series’ past: In the exclusive clip above, Mulder (David Duchovny) pays his respects at the grave of Kim Manners, who produced and directed much of the show’s original run.

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“It was almost dreamy,” says Darby of the atmosphere on set. “People were always wanting to certainly do their best to make sure that the legacy continues.

“Everyone was excited to be making the show again.”

One of those excited faces was Darby’s fellow guest star, Silicon Valley‘s Kumail Nanjiani, whom he’d met before — although never like this. “I didn’t know how much of an obsessed fan he was,” Darby says. “We shared our enthusiasm and nerves, and then of course when we were around the people we just played it cool. I said to him, ‘Look, just play it cool. Make it look as though you’re not really into it.’ And he said, ‘Well, it’s a bit hard to do.’ I mean, he’s got a podcast all about it.”

“So I said, ‘Oh, you’re screwed. I’ll just play it cool myself,’ ” says Darby. “So I did.”

But the time for playing it cool has passed. Darby, who hasn’t yet seen the finished product, says, “I’m just as excited as all the X-Files fans to watch the episode. The only difference is that I’m in it.

“Apart from that, just as excited.”

The X-Files airs Mondays at 8 p.m. ET on Fox. Check out the video above for an exclusive look at Darby and Duchovny in action.