The Twin Peaks reboot is coming in the first half of 2017... and that's about all Showtime can say about it.

David Nevins, president and CEO of Showtime, and Gary Levine, Showtime's president of programming, revealed that there's still not a set number of episodes for the series at the Television Critics Association fall previews on Thursday.

"In terms of the number of episodes, it's a fluid process," Levine said. "[For creator] David Lynch, it's a process of seeing how it evolves, and that organism continues to evolve until he thinks he's figured it out."

Levine said Lynch "personally carried binders" full of ideas he and Mark Frost have compiled over 25 years to show the Showtime suits, but none of them were in fully formed scripts. "Some of [them] they had been musing about for 25 years. It was never a prescribed number of episodes in that way," he said.

Catch up on all the latest news from TCA

Showtime aired a brief behind-the-scenes clip of Twin Peaks before the panel, which mostly consisted of a handful of the show's 217 actors talking about how excited they are about the project over shots of mountains and trees. Nevins and Levine have only seen dailies, but will start seeing cut footage next week.

Here are other highlights from the panel:

Penny Dreadful's cancellation: Series creator John Logan announced that the drama was canceled the day after its third season finale in June, which came as a surprise to lots of fans. But Logan always meant the series to last three seasons because he designed it around Vanessa Ives' (Eva Green) story, which came to an end in the Season 3 finale. "I think in John Logan's mind it was always three and out," Nevins said. "We were trying to keep it open for three or more. It just became [clear] that trying to keep the show alive past the life of Vanessa Ives ... was foolhardy. ... John didn't want to continue beyond that character."

Levine said they chose not to announce the show's end beforehand because Logan "didn't want to cast a pall on the final season and he didn't want to tip off the death of Vanessa Ives."

Recruiting Saturday Night Live stars: How pissed must Lorne Michaels be at Showtime? Days after both Jay Pharoah and Taran Killam were dropped from SNL, Showtime revealed that both actors will star in new comedies for the network. Nevins said he never had discussions with Lorne — just with the actors — about the projects, but he was willing to accommodate their SNL schedules. "We were prepared to work around their SNL schedules," he said, adding that Pharoah and Killam were both on the last year of their SNL contracts. "Our schedules got easier when they got released from the show."

Homeland's three-season renewal: Showtime has completed a multi-year pickup for the drama through Season 8, but no one has any idea what's going to happen story-wise beyond Season 6, which premieres Sunday, Jan. 15. "This show is broken year by year. It's somewhat anthological in that way," Nivens said. "[Executive producer Alex Gansa] is comfortable doing two more seasons after this season and we'll sort of see [after that]."

Will Roadies ride on?: "We're still evaluating what its future is one way or the other," Nivens said of the Cameron Crowe series, which hasn't exactly set the world on fire.

Colbert Nation on Showtime?: Nivens revealed that discussions are underway for Stephen Colbert to host a live comedy special on election night. "Stephen wants to do it, I want to do it," he said. "He's promised to say some curse words, which is important to me."

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