Fans of The Room and The Disaster Artist may have been surprised to see Greg Sestero appear in the Netflix horror series The Haunting of Bly Manor. In the new series from creator Mike Flanagan, Sestero can be seen in the very first episode seated at the table as Flora's fiancé. Undoubtedly, many of us who've seen The Room couldn't help but exclaim, "Oh, hi Mark!" as soon as Sestero appeared on the screen. As it turns out, Flanagan is also a fan of the cult classic movie along with Sestero's book about its creation, and it was this appreciation that led to the seemingly-random cameo.

Talking about his involvement with The Haunting of Bly Manor, Greg Sestero revealed that Flanagan was such a big fan of the book that he had actually approached Sestero years ago about turning The Disaster Artist into a movie. Unfortunately for Flanagan, James and Dave Franco had already started the process by that point. Still, it was just a matter of time before Flanagan found another way to use Sestero, resulting in his role in the popular Netflix series.

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"So, my first time ever doing a horror convention kind of thing, [Flanagan's] wife Kate Siegel came up and was super cool, and said, 'My husband would like to give you a cameo.' I thought it was a joke. But it's funny, because now I can't say that The Room didn't get me acting work, because it finally paid off and put me in something that's good."

While The Room would become a cult hit, Sestero would become more well-known with mainstream audiences when the movie adaptation of The Disaster Artist was released to great success. Directed by James Franco, it stars Franco as Tommy Wiseau alongside brother Dave as Sestero. The acclaimed movie earned James the Golden Globe for Best Actor for his portrayal of Tommy and it was up for an Oscar for Best Adapted Screenplay at the Academy Awards. Flanagan was right to see the potential in the story, even if the Francos were just one step ahead of him.

Meanwhile, Flanagan has also been doing just fine with his acclaimed work in the horror genre. He created The Haunting of Hill House for Netflix in 2018, based on the classic Shirley Jackson novel of the same name. Rare for a horror series, the show was universally praised by both critics and viewers. Last year, he also released the Stephen King adaptation Doctor Sleep to great reviews, and following Stanley Kubrick's The Shining is certainly no easy feat.

The Haunting of Bly Manor has no storyline connection to Hill House, but the series does bring back many of the same actors. Victoria Pedretti, Oliver Jackson-Cohen, Henry Thomas, Kate Siegel, Carla Gugino, and Catherine Parker are all back, but in different roles. Amelia Eve, T'Nia Miller, Rahul Kohli, Tahirah Sharif, and Benjamin Evan Ainsworth also star. The series is streaming now on Netflix. You can read the rest of Sestero's interview speaking about his involvement with The Haunting of Bly Manor at Nerdist.