“Mark Frost has all the answers,” says Kyle Mac­Lachlan, star of Twin Peaks: The Return. “He’s the guy you want to listen to.”

In Showtime’s 18-episode revival of the 1990s cult classic Twin Peaks, clarity was notoriously hard to come by. “What year is this?” Mac­Lachlan’s Agent Dale Cooper asks in the finale, underscoring the difficulty in this world of nailing down even the most basic information. Instead of answering him, Sheryl Lee, returning as murder victim Laura Palmer, lets loose a piercing shriek as the screen cuts to black. Her screams might as well have been those of countless Twin Peaks fans left with more questions than ever before.

But Mark Frost, who created the original series as well as the revival alongside David Lynch, had answers, and he shared them with those who knew where to look. His companion book to the series, Twin Peaks: The Final Dossier, became a best-seller last year and a source for fans to find intel on everything from what’s going on with fan favorite Audrey Horne (Sherilyn Fenn) to the haunting question that ended the original series’s run: “How’s Annie?” Though Lynch, the compellingly eccentric other half of the Twin Peaks founding duo, tends to get all the press attention (along with four of Twin Peaks: The Return’s nine Emmy nominations; he and Frost share one for writing), Frost is the one who’s shown at least some willingness to reveal the secrets of the kingdom.

Frost’s hair, like Lynch’s, has gone snow white since Twin Peaks changed both men’s lives in 1990. Frost wears his swept back in a more subdued version of Lynch’s famous quiff, and he speaks warmly and directly, with none of his partner’s signature discursive style. He called a little late on a Saturday afternoon—his son’s baseball practice had run long—from his home in Ojai, California, where he and his wife moved to escape Hollywood more than a decade ago.

“I didn’t pay any attention to it,” Frost says of the mythology that has grown up around Twin Peaks since it first aired. “I was doing other things, you know?”

When the original series ended its run, in 1991, Frost returned to his first love: literature. The man who wrote three novels before the age of 15 has since published three nonfiction books on golf, including The Greatest Game Ever Played—adapted into a 2005 film starring a young Shia LaBeouf—and several more novels, including a young-adult trilogy with the Peaks-ian title Paladin Prophecy. But none took off in the same way as his epistolary novels, 2016’s The Secret History of Twin Peaks and 2017’s Twin Peaks: The Final Dossier, which see Agent Tammy Preston (played by Chrysta Bell in The Return) digging into the occult history and tragic present of the mysterious logging town.

When Frost and Lynch first met, in the mid-80s, Frost was already a fan of the director’s early work: the experimental *Eraserhead *and Oscar-nominated The Elephant Man. Having cut his teeth writing for network TV shows such as The Six Million Dollar Man and Hill Street Blues, Frost, in his early 30s, was introduced to Lynch over—what else?—a cup of coffee. The pair hit it off and, after a few joint projects failed to launch, landed a deal with ABC to co-write Twin Peaks, about the mysterious murder of a teenage girl named Laura Palmer and its impact on a small Pacific Northwest town. “It is doubtful whether ABC would have gone for one partner without the other,” Richard Woodward wrote in a 1990 New York Times profile.

For a brief time, Frost’s down-to-earth narratives blended seamlessly with Lynch’s surrealist style. “It’s impossible to remember who wrote what or who did what, but David liked coffee and I liked pie. I know that much,” he said in an interview a decade later, divvying up credit for the treats preferred by Mac­Lachlan’s Agent Cooper. The show netted record ratings as it expanded its fan base, setting a model for obsession-worthy television that was well ahead of its time.

But it wasn’t easy being pioneers. Frost said in 1990, “You always get to that point [of disagreement]. I’d never written with a partner before and neither had David, and what you quickly realize is that it’s quite a bit like a marriage.” Lynch, who directed a number of the show’s early episodes, would change scripts in order to pursue avenues of divine inspiration—such as the dreamlike Red Room, which became a staple of the show’s iconography. Frost wasn’t always happy about it: “I had a few doubts about the midget.”

If the first, sublime season of Twin Peaks was the honeymoon period for the creative partners, by Season Two they were nearing divorce. Lynch has said that the network killed his interest in Twin Peaks by insisting that he and Frost reveal the identity of Laura Palmer’s murderer. The network suits weren’t the only ones; according to one published rumor, no less a personage than Soviet Union leader Mikhail Gorbachev asked then president George H. W. Bush to pry the secret from Frost and Lynch. Under duress, the murderer was revealed midway through Season Two, and Lynch all but washed his hands of the project.

“I don’t think David and Mark ever wanted to really solve the mystery,” Mac­Lachlan tells me. “I think they were quite content to just let it kind of be a continuing investigation, so that we could all enjoy these crazy townspeople and other entities surrounding the world of Twin Peaks.” He’s half right. “I know David was always enamored of that notion, but I felt we had an obligation to the audience to give them some resolution,” Frost said in a 2000 retrospective in Entertainment Weekly. “That was a bit of tension between him and me.”

After Lynch’s de facto departure—he would return to direct the series finale—the show tanked in the ratings and was abruptly canceled. Lynch pounced on the opportunity to reclaim creative control of the story with a follow-up movie, 1992’s Twin Peaks: Fire Walk with Me, which pre-dated the action of Twin Peaks and explored the final days of Laura Palmer. This time, it was Frost who was uninterested. “David and I had a disagreement about what direction a movie should go,” he told the Twin Peaks fanzine Wrapped in Plastic. “I felt very strongly that our audience wanted to see the story go forward.”

Wrapped in Plastic, which launched in 1992, was a print publication, but Twin Peaks fandom truly grew on the nascent Internet. “I’ll never forget the first time somebody brought in a stack of transcripts of—at the time they just called them forums—where people would go in and ask questions,” Frost recalls. “It was the precursor to the world we now just take for granted. But this was a stack of papers the size of the old English dictionary.”

Mädchen Amick, who plays Shelly Briggs, née Johnson, says, “I feel Twin Peaks is the show that first brought that to the viewer. Then it became an obsession, right? It became the perfect instrument to tap into—the way David did it—the yucky, icky, bubbling, dark secret beneath the perfect town. Everybody’s fascinated with that.” Because Lynch tended to divulge as little as possible, amateur theorists rushed in to try to answer all the lingering questions. “It gives room for the fans if they want to engage with it that way, to bring something of their own to the experience,” Frost explains. “I wouldn’t say that it was a deliberate intent, but it certainly was a by-product that none of us regret. If you judge by the results, it seems to be effective in drawing people in and keeping them engaged.”

That debate over what it all might mean kept Twin Peaks alive in the cultural conversation, growing the series into a bona fide cult phenomenon that inspired festivals, books of scholarly essays, and a new generation of mystery-laced TV shows, from The X-Files to Riverdale. It’s hard to think of any modern series that wouldn’t want to inspire its own version of a “Who Killed Laura Palmer?” obsession.

To illustrate the magnitude of that mania, Frost describes visiting the set of Twin Peaks: The Return and meeting fans who said the original series had inspired them to move to Washington. “This wasn’t just remembering the theme song to Gilligan’s Island,” Frost says. “This was people re-purposing their lives to sort of swim in that same slipstream of place and identity.”

By 2014, Showtime wanted a piece of the obsession. Network chief David Nevins calls it “the original social-media show, the original discussion show—before any of the tools of discussion and social media and fan engagement really existed.”

So, how did Frost and Lynch overcome their creative differences and get the band back together? Apparently, by embracing flexibility. “It’s not just all Lennon-McCartney songs,” Frost says of their new arrangement. “There’s some separate songs by each of us. So it’s a little more like ‘the White Album,’ I guess, when you really think about it, than it is Sgt. Pepper.”

The pair wrote the new scripts for The Return together—re-creating their old rhythm thanks to the use of Skype. Frost did all the actual typing in this collaboration because, as he once joked, Lynch “literally can’t type his name.” The increased weirdness of The Return, though, attests to the fact that Lynch, who directed every episode, and even, at one point, publicly threatened to walk away from the entire project if he didn’t get the budget he wanted, had insisted on full and final creative control of the series. “David is the only cook,” Mac­Lachlan says. “That’s it. He makes what he believes in, and what speaks to him, and no one else interferes or alters.”

Frost, for his part, had free rein to answer every remaining question in his companion books—Twin Peaks: The Secret History and Twin Peaks: The Final Dossier. After he and Lynch worked together to create the bones of The Return, there was a separation of church and state. “I think the show, for the most part, is the point of view of two people,” Frost tells me. “It’s David and I, and we wrote the scripts together, and he directed the show, and I wrote the books. And I think it’s both of us giving what we did together an expanded sense of what we might think about that same thing individually.”

Mac­Lachlan, who had his own frustration with the end of the original run of Twin Peaks and agreed to appear only minimally in Fire Walk with Me, says The Return was inspired by all “the questions [that] were never answered.” At the same time, Mac­Lachlan calls Lynch’s insistence on refusing to resolve those questions “amazing. We all want answers, and it can be very frustrating, but art is not there to answer. It’s to promote questions, more questions, and I think that’s what David does so beautifully.” (It’s worth mentioning that Mac­Lachlan, like everyone I spoke to, was under strict instructions not to explain anything left ambiguous by the show’s ending.)

In The Return, Lynch and Frost managed to go back in time and muddle the one certainty in Twin Peaks lore: the identity of Laura Palmer’s killer. The Return’s finale undoes her death entirely, showing her body, famously wrapped in plastic, vanishing from view.

And in The Final Dossier, Frost, now seemingly more comfortable with Lynch­ian ambiguities, allows for both versions of the story to be true. The book’s narrator, Tammy Preston, knows Laura Palmer was murdered, but when she goes back to read old accounts of the crime, all evidence of the teenage girl’s demise has vanished. When she interviews people in the town, they are confused and foggy as to what the truth real­ly was. “What I wanted to do,” Frost says, “was take chances with the overall narrative and challenge people in the same way that the show did with some of those realities, many of which contained contradictions, which is also part of the human experience.”

But Frost also tucked away tidbits on characters neglected during the script-writing phase for The Return to include in The Final Dossier. In those pages Frost explains what happened to such original, core Twin Peaks players as Donna Hayward (played by Lara Flynn Boyle), Annie Blackburn (Heather Graham), and Harry Truman (Michael Ontkean)—all of whom were missing from The Return.

Frost’s most satisfying contribution concerns Sherilyn Fenn’s Audrey Horne— whose confusing absence from the reboot until her even more baffling reappearance in its back stretch was a particular sore spot with fans. “I don’t know that I consider anything in The Return a disappointment,” says Karina Longworth, a Twin Peaks super-fan who hosts the popular You Must Remember This podcast. “But I had really gotten into this thing of Audrey as a girl detective. It was difficult to see her older and so vulnerable.”

Audrey Horne, who was once, according to Fenn herself, supposed to get her own spin-off movie, shows up in only a handful of scenes in The Return. She’s abrasive and anxious, and many viewers concluded that, in the decades between the original series and The Return, she had been not only institutionalized but also sexually assaulted by an elemental force of evil. It’s a frustratingly cruel treatment of a beloved character.

In the books, Frost fills in the gaps of Audrey’s story, including her sexual assault, pregnancy, separation from her family, marriage of convenience to her accountant, and subsequent disappearance from all public life to, rumor has it, a private care facility. Those sad background details help make sense of her frustrating behavior. “The reactions I’ve gotten have been mostly ‘Thank you,’ ” Frost says. “Her story in particular was fairly oblique in the series, and there were things to say there that I think were probably better said on the page than on the screen.”

His latest Twin Peaks book title may include the word “final,” but Frost hopes the show will continue. Lynch, for his part, politely declined an interview for this story, explaining via a representative that he had moved on from Twin Peaks and was focused on his painting.

Fortunately, fans of this franchise have learned to be patient. They know that the true magic happens on those rare occasions when Frost’s and Lynch’s creative moods align. You can’t have the coffee without the cherry pie.