Levi Holloway on his psychological thriller starring Laurie Metcalf: “It wears the jacket of horror. But I think it’s more heart than horror.”When it comes to plays that inspire fear, unsettle the audience or display horrific intensity, only a handful come to mind. Martin McDonagh’s gruesome “The Pillowman” is one. Tracy Letts came up with two: the gleefully nasty thriller “Killer Joe” and the paranoia tale “Bug.”This certainly makes Levi Holloway’s “Grey House,” now in previews at Broadway’s Lyceum Theater, an oddity. The premise is classic horror: Stranded in a blizzard, a couple (Tatiana Maslany and Paul Sparks) end up in an eerie house filled with rather unusual children and their minder (Laurie Metcalf).“It wears the jacket of horror,” Holloway said of his play, which premiered in Chicago in 2019. “But I think it’s more heart than horror.”Paul Sparks, center, as a stranded traveler who finds shelter in a house occupied by, clockwise from left: Colby Kipnes, Sophia Anne Caruso, Eamon Patrick O’Connell, Millicent Simmonds and Alyssa Emily Marvin in “Grey House.”Sara Krulwich/The New York TimesThe genre may be scarce onstage but none of the major players here are strangers to works investigating disturbing tensions or the boundaries of reality. Metcalf and Sparks share a Stephen King connection: she starred in “Misery” on Broadway, and he was in Season 2 of Hulu’s “Castle Rock,” which is set in King’s fictional universe. Maslany’s virtuosic portrayal of numerous clones in the series “Orphan Black” earned her an Emmy Award. Millicent Simmonds played Emily Blunt’s daughter, Regan, in “A Quiet Place” and “A Quiet Place Part 2,” while Sophia Anne Caruso played Lydia in the “Beetlejuice” musical on Broadway and starred in the Netflix fantasy film “The School for Good and Evil.”Even the director, Joe Mantello, has partaken, putting on his actor’s cap to play a reporter in “American Horror Story: NYC.”During a series of interviews that took place in the Lyceum’s appropriately atmospheric basement lounge, members of the show’s cast and creative team discussed what horror means to them, and the particular challenges and rewards of “Grey House,” which opens on May 30. These are edited excerpts from those conversations.Levi HollowayWhen Holloway was 5, his father took him to see “A Nightmare on Elm Street” in a movie theater. “The skin was taken off of me,” Holloway said, “I was so scared.”Undeterred, his father eventually bought him a subscription to the horror film magazine Fangoria, so young Levi could understand the mechanics of fear. To encourage his kid to read, Dad gave him books by Stephen King, starting with “The Stand.”As a playwright, he has embraced horror partly out of genuine love (he mentioned John Carpenter’s “The Thing” as a favorite, and don’t get him started on why “The Exorcist III” is the best of the series) but also as a way to process a major trauma: In 2016, his twin sister was killed at the age of 35. “It was so meaningless and pointless, and such a baffling event that it got me thinking about the why of it,” he said.“I started thinking about predestination and fate and how no matter what direction we’re going, we’re going to end up where we have to be,” Holloway continued. “So I wanted to write about that, and I wanted to write about grief, where you put it and the house that holds it.”Caruso, left, and Metcalf, who plays a minder of a group of children, in the play, directed by Joe Mantello.Sara Krulwich/The New York TimesSophia Anne Caruso“Mind games, manipulation, psychological thrillers in general are the scariest genre of quote horror to me,” Caruso said. “And I think that this play definitely sits in the ‘psychological thriller’ section of horror.”The young actress has her issues with the genre, in which she sees women as often losing power. “But throughout this story, we are holding a lot of power without people directly realizing it,” she said of the play’s women. (Well, maybe not all of them.)“What I love about my character is I feel like she’s always one step ahead,” Caruso said of her role, which makes the most of the actress’s gift for sardonic delivery. “She knows exactly where we’re going but she doesn’t show it, and that’s a fun frustration to play with.”Joe MantelloBefore rehearsals began, Mantello watched “The Shining,” in which he saw parallels with Holloway’s play. “It’s a psychological thriller and, yes, there are elements of gore in it, but I think it was the isolation of that family in a very wintry landscape,” he said of the Stanley Kubrick film. “And some presence that is altering the trajectory of their lives.”As one of Broadway’s most in-demand directors, Mantello is used to figuring out exacting scripts, but he initially found the one for “Grey House” to be elusive. So he asked Holloway what animated the play’s inner logic. “I think that it’s important in this genre that this world has a particular set of rules, this house has a particular set of rules,” Mantello said. “Though the audience may not ever completely comprehend exactly what those rules are, we all have to be crystal-clear about them and adhere to them.”The “grey house” is not just a physical place, either: it seems to connect to a generalized anxiety that feels very modern, even though the show is set in 1977. “I feel that the world is in an incredibly dangerous place right now, and I’m very connected to the idea of people in peril,” Mantello said. Laughing, he added, “In this particular case, the danger is seemingly benign children, mysterious children.”“Leading the audience through the laughs into where we’re headed is a real fun actors’ path to take,” said Metcalf, above right, with Holloway at the Lyceum Theater.Mark Sommerfeld for The New York TimesLaurie Metcalf“The thing that shook me the most was ‘The Exorcist,’” Metcalf said of her earliest encounters with horror films. “I think I was in my early teens and that did me in for horror for the next 50-something years.”And now here she is, starring in “Grey House.” Metcalf was drawn by the prospect of working again with Mantello, her frequent collaborator, and she was curious as to how he would handle a script that, she admitted, she did not “completely understand” the first time she read it. “I knew that Joe saw something in it that I wanted to be in the room to discover also,” she said.The show has to balance a tricky combination of dark wit and unsettling atmosphere. “The audience is going to teach us that piece of the puzzle — their reactions will definitely tell us a lot,” Metcalf said of how the comedy and horror genres thrive on viewers’ feedback. “We’ll learn how far we can go with the humor and the thrills.”She added, “I had the same feeling in ‘The Beauty Queen of Leenane,’ which is horrific and funny,” Metcalf said, referring to performing in the Steppenwolf production of Martin McDonagh’s play, back in 1999. “Leading the audience through the laughs into where we’re headed is a real fun actors’ path to take.”Millicent SimmondsAs Caruso pointed out, genre cinema, especially horror, can be a fraught place for women. For Simmonds, who is deaf, there is an additional layer. “It’s rare to see Deaf people who actually have that kind of power and agency to navigate a world,” she said of her character, through an interpreter. “They’re often portrayed as victims, a pity creature, somebody to help. When I read the script,” she added, “it was about just a person, not necessarily that they’re a Deaf person.”Simmonds said that in general she has a hard time dealing with spiders and graphic violence in films, and cited Darren Aronofsky’s “Black Swan” as having affected her “because you don’t know what’s real and what’s not” — something that also applies to “Grey House.”Cagey, like her colleagues, about discussing the play in detail, Simmonds allowed that she sees it as a maternal story. “It investigates this question of what is a mother,” she said. “What does a mother mean to each of us? What do you need to sacrifice to be a mother? How do you raise a family?”Paul SparksLike Mantello, Sparks connected the show to a larger sense of dread that is haunting our society, a sense that our world is unsettled. “There’s a lot of things that we can’t control and things that we don’t understand, and things that aren’t what we think they are,” he said. “All that stuff is in this play.”The actor pointed out that “Grey House” uses a major horror trope, the cabin in the woods. But Holloway spins it in a novel way, inserting a cryptic side to the story that made Sparks want to pick it apart, and decode it.But he hopes audiences show some restraint in how much they share after seeing it. “I’ve been really going out of my way to not tell people anything about what’s going on,” he said. “These actors, these kids — I think people are not going to know what to expect. And it’s not even going to be close to anything they can imagine.“I think you’re going to be shocked,” he added. “I really do.” More