James Frankie Thomas isn’t stuck in high school. He can, however, recall with crystal clarity every role he played onstage from the ages of 14 to 18. “I wish I could pretend that I don’t remember, but I think about it every single day of my life,” he says, joking but not joking as he picks at a piece of pecan pie. To be fair, you’d feel that way too if you’d played Puck, the titular role in Kiss Me, Kate, and Little Red in Into the Woods.

Anyone who’s impressed by that list will be even more bowled over by Idlewild, Thomas’s debut novel, which hit shelves this week. Set at the turn of the 21st century, the book follows Nell and Fay, teenage best friends so inseparable that a third of the book is narrated by a collective consciousness called the “F&N unit.” Fay and Nell are unabashed theater kids, and they’re also both slightly tortured: Nell is a lesbian who once harbored a hopeless crush on Fay, but Fay only has eyes for beautiful boys like Theo, a mysterious new sophomore. Not because Fay wants to sleep with Theo—or at least, not only for that reason—but because Fay wants to be Theo.

Thomas, who graduated from high school in 2005 and from the Iowa Writers’ Workshop in 2019, understands melodramatic elder millennials as well as Curtis Sittenfeld understands old money prep school kids. Fay and Nell are always slurping elaborate Frappuccinos and writing covert fan fiction over AOL Instant Messenger. Their very first conversation hinges on those quarters that had different designs for all 50 states—remember them?

“I think I am capable of writing characters who are nothing like me, but I was not interested in doing that for this book,” Thomas says over coffee in August. (Like Fay and Nell, he also did On the Town in high school, though he’s got a connection to the show that they don’t share: Thomas’s grandfather is Leonard Bernstein.) “I was interested in writing about being on the outside of what is considered a normal high school experience—specifically, being queer and not having a dating life, not having the sort of YA novel experience of coming out and blossoming in high school.”

The result is a book that’s almost painfully relatable for somebody who’s in the same microgeneration as Thomas, whose research involved rereading both his old diary and the “incredibly detailed blog” he kept his junior and senior years. Unlike Nell’s LiveJournal, Thomas’s Blogspot was not protected by reader permissions. “A lot of drama ensued from the fact that it was public.”

But Idlewild’s pleasures aren’t accessible only to the relatively small group of people who appreciate the nuances between a Blogspot and a LiveJournal. There’s something universal in the book’s careful excavation of complicated relationships, its compassionate understanding of how friends at that age can love and resent and envy and condescend to each other all at once.

“My first kiss was not the most exciting moment of my teen years,” says Thomas. “My sexual exploration was not the most interesting thing about my senior year. What I remember instead is the yearning and the friendships that I had, and wondering what people thought of me.” The ties between Fay and Nell and the boys they get entangled with—possibly sociopathic Theo and gentle, passive Christopher—“don’t have an easy label and don’t fit into familiar categories. And that was the thing I really, really wanted to explore in fiction, because I so rarely see it explored.”

In our post–Gone Girl world, it’s also rare to find a page-turner that doesn’t have a gimmick—competing timelines; narrative bait-and-switches; crucial information that, while known by the characters, is withheld from the reader until the very last minute.

Thomas can understand why authors are so tempted to pull that last trick: “It’s because it’s fun. It’s like edging.” An early draft of Idlewild even employed it. Originally, the book was framed by Fay and Nell preparing to reconnect at their 15-year high school reunion. “I think I didn’t trust that the story of their time in high school was enough for a novel for adults,” he says, “and so I kept trying to bring in present-day storylines and themes”—as well as a very contemporary, literary-thriller-esque twist.

“Theo was always a major character, but I kept trying to imply that he’d done something really bad as an adult, and the whole novel was working toward the revelation of what he’d done. And I wasn’t even a hundred percent on what that thing was.” Thomas’s Iowa classmates had a running joke that Theo must have been involved in getting Donald Trump elected.

Thankfully, Thomas’s thesis adviser told him to instead focus more acutely on Nell and Fay. In the process, Idlewild became a whydunit—a story about how their bond eventually breaks. The idea, he says, owes a debt to his all-time favorite novel, The Secret History. “Donna Tartt lays out the solution to the whodunit on page one. So the mystery that keeps you turning the pages is not who killed Bunny, but the question of: Why did this happen? Why did you do this? How did this happen?”

There are similar questions inherent in Theo’s relationship with Christopher, and “it’s not a coincidence,” says Thomas, “that I gave just enough material that one could write fan fiction [about them] in multiple imaginative directions.” Fan fiction wasn’t a huge part of his life as a teenager—“I was a snob as a teen”—but it became one in his 20s and 30s, particularly as he began understanding his identity as a trans man more fully.

It’s not a spoiler to say that Fay ends the book inhabiting the same body they’ve had since high school—a conclusion that strikes many readers as grim. Thomas doesn’t see it that way. “People who have actually transitioned, they do not read Fay’s ending as bleak,” he says. “They read it as hopeful, because they can recognize that the agony that Fay is in at the end is actually part of a process that is just kicking into gear.” It’s a feeling Thomas knows all too well: He didn’t begin his own transition until after he finished the first draft of Idlewild. “I didn’t know how T would affect me psychologically, and I thought, I’m so, so close to finishing this novel. Let me just stay in this headspace.”

He continues: “What I wonder now, thinking back on it, is if this bleak ending is almost physical evidence of a preteen mindset. If it came out of a brain that just felt, on some level, hopeless. I wonder if I would’ve written a different ending if I had started T while I was writing it. It’s not knowable, but it is an interesting question.” And either way, he doesn’t buy that people can’t fundamentally change after high school—even recovering theater kids. “I think life is very long, and they’re 33 at the end of the book. Thirty-three is nothing. Thirty-three is not the end of your life. There’s so much life left after age 33.”