The X-Files writer Glen Morgan teases 'Home Again', and a big showcase for Gillian Anderson

When writer-director Glen Morgan was looking to cast a character in Monday’s episode of The X-Files, he turned to an unexpected place: his music collection.

Rancid frontman Tim Armstrong guest-stars in “Home Again,” the fourth hour of The X-Files‘ six-episode event series, as the Trashman, a street artist who — as seen in the exclusive clip below — may have a connection to a series of unexplained murders. For Morgan, who calls himself “the biggest Rancid fan,” Armstrong’s casting was a leap of faith.

“I wrote [‘Home Again’] with him in mind,” Morgan tells EW. “And then when I was done, I figured out who the manager might be and I wrote a real professional, kind of square letter going, ‘Hey, would he be interested?’

“About 15 minutes later, the manager wrote back, ‘Oh my God, this is the email of the month.’ “

Armstrong was on board, and The X-Files got more than a guest star out of the deal. “The set you see, the artist’s studio, that’s all his artwork,” Morgan says. “Along with Gillian Anderson’s daughter, who worked in the art department. Piper did a lot of the work in the Trashman’s studio. It was the only time I’ve ever seen Gillian taking pictures of the set, because her daughter had done it.”

Morgan teases the episode as a showcase of Anderson’s talents as well. “Gillian Anderson is extraordinary,” he says. “I just want everybody to see her performance.

“I would go on and on about how extraordinary Gillian is.”

The X-Files airs Mondays at 8 p.m. on Fox. Check out the exclusive sneak peek at “Home Again” below, and stay tuned to EW after the episode for Morgan’s full postmortem thoughts.