Plus, Allison Tolman joins an all-star cast of TV favorites in the Hulu limited series inspired by the Stephen King multiverse.

When Sam Shaw and Dustin Thomason made Stephen King scream at his TV, they knew they’d done him proud.

“After he watched the first episode, we were really excited because he said that for the first time in a very long time, he called out to his TV to tell someone to not go where they were about to go,” Thomason said during a panel discussion for his Hulu series “Castle Rock” Friday afternoon.

“Yeah, especially because he’s the guy who made a career out of sending people into places that they should not go,” Shaw said.

Making their first public appearance to discuss the Hulu anthology, co-developers and executive producers Shaw and Thomason debuted an exclusive four-minute clip at the ATX Television Festival in Austin, TX, and then spoke for 45 minutes about how the mysterious anthology show came to be. But without the friendship between another executive producer and King, the highly anticipated drama may never have been made.

“J.J Abrams is a huge Stephen King superfan and he opened up the possibility of doing the show,” Shaw said.

Abrams formed a friendship with King while his ABC drama “Lost” was on the air, Shaw said, noting how King was a vocal fan of the show — writing reviews for Entertainment Weekly — and often spoke to the co-creator and producer about his work.

“This is where J.J. becomes the ingredient without which none of this is possible,” Thomason said. “J.J. not only has a very strong relationship with Stephen King, but also Warner Bros. […] and Warner Bros. was the studio behind some of the biggest and most iconic King films, so there was no other way to do it. We wouldn’t have been able to do it without access to all that material.”

“Castle Rock” draws on multiple Stephen King projects, including novels and film adaptations. Everything from “The Shawshank Redemption” to “Cujo” finds their way into the episodes either as settings, references, or even more subtle tie-ins. Basically any project featuring the fictional town of Castle Rock — a favorite Maine locale for the author — is fair game for the Hulu show.

“Stephen for us was like Charlie in ‘Charlie’s Angels,’ He was more like a crucial figure who loomed large from afar,” Shaw said, noting how King preferred to write new novels than dwell on Hollywood adaptations. “Now he’s focused on doing his own work. So there were early conversations about getting his sanction and blessing because even with Warner Bros. controlling the rights and saying ‘Go ahead,’ Castle Rock is an important town in the Stephen King library — it’s pretty important to him — so we needed and wanted to have his blessing.”

So how did they earn that blessing? Shaw credited Abrams, though the footage shown certainly speaks for itself.

“We were really gratified when he said yes, in part because we weren’t the first people to knock on his door asking for a cup of sugar — and to please be able to set a TV show in Castle Rock,” he said. “It’s probably just the strength of his relationship with J.J. that made this possible.”

Shaw and Thomason also confirmed that “Fargo” star Allison Tolman will be a recurring star in Season 1. She plays the sister of Melanie Lynskey’s character; a part she got after innocently congratulating Lynksey on Twitter for landing her part.

How exciting! Do not know the script but available to play your sister. Xx. — Allison Tolman (@Allison_Tolman) June 28, 2017

“It’s actually a great story,” Thomason said. “When Melanie was cast, there was a casting announcement and Allison saw the announcement and tweeted at Melanie — and they did not know each other. […] But the weird thing is, we knew she had a sister [but Tolman didn’t]. Of course Allison would’ve been someone we strongly considered, but as soon as she said that, we thought, ‘Allison Tolman would be the perfect sister!'”

Tolman joins a cast list that includes Lynskey (“Togetherness”), Andre Holland (“The Knick”), Sissy Spacek (“Carrie”), Scott Glenn (“The Leftovers”), Terry O’Quinn (“Lost”), and Bill Skarsgard (“It”). Between Spacek and Skarsgard’s cinematic connections to King, as well as O’Quinn’s “Lost” connection and the rest of the cast’s sterling credentials, it’s shaping up to be one of the most exciting groups brought together in some time.

But they won’t all be coming back should “Castle Rock” earn a second season.

“The show is kind of a seasonal anthology show,” Shaw said. “This season is a 10-episode season — it’s one 10-episode story — and there are tributaries along the way and different points of view, but essentially one story that runs its course throughout these episodes. And there are some Stephen King characters who are really important to the story, and then there are a lot of original characters that kind of share some DNA with characters from Stephen King classics.”

How did King feel about sharing his characters with new scribes?

“There were moments when we wanted to do something kind of unorthodox with his characters and we had to make the call and on bended knee ask if he was cool with it,” Shaw said. “And he was always really great and flexible and gave us real license.”

“You go into an experience like that hoping Stephen King is cool, and it turns out he’s really cool,” he said.

So far, it seems like the feeling is mutual.

“Castle Rock” premieres the first three episodes July 25 on Hulu with new episodes debuting each following week.

The ATX TV Festival runs in Austin, TX from June 7 – 10. For more information, visit the official website.

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