“Awkward sex.”

That’s Theo James’ response to the question, “What is your greatest fear?” I’m here on the Chicago set of Divergent, a film adaptation of the wildly popular young adult novel, and James, who plays the male lead, is looking much foxier than when I last saw him as Mr. Pamuk on Downton Abbey. He cracks a sly grin, then tries to get serious. “I used to have this reoccurring dream where I was constantly climbing a set of vertical stairs, and I think that’s from when I was a kid. I think I fell back off some stairs and fucked up my head. So that would be one. Bananas would be another. I hate bananas.” His dark eyes glitter with amusement, but the tense square of his jaw makes me wonder if he’s kidding. (A jaw like that is very distracting.)

The other members of Divergent‘s young cast are equally as candid in their responses. “Open water. What’s in there?” wonders Amy Newbold, a former casting director who’s taking a break from her nursing career to take on the role of Molly, one of the movie’s antagonists. “Also,” she says, “broken glass.” Her costar and fellow villain Miles Teller can’t resist teasing her before confessing that he worries about his grandparents getting older. Unable to stay solemn for more than one minute at a time, he adds, “I don’t like snakes, but that’s not a fear. I just think they’re weird.” Jai Courtney, who plays a highly intimidating military leader and is therefore the toughest-looking guy on set, admits that he’s pretty claustrophobic, so tight spaces are frightening. It makes perfect sense given the size of his biceps.

Even without the aid of their futuristic special ops uniforms, it’s easy to picture these actors as members of Dauntless, the punk rock clan of warriors who maintain security for a dystopian version of Chicago. In the world that author Veronica Roth has created, humans are divided into factions based on their character traits, and if you happen to enjoy knife throwing, zip-lining between skyscrapers and beating the crap out of people, then Dauntless is the place for you. (It’s basically the badass version of Gryffindor.) The faction is ruled by a carpe diem attitude and a thirst for life, neither of which is in short supply on the Divergent set. Crackling with charisma, this cast is a force to be reckoned with, so it’s no surprise that, when asked to pick a faction, the vast majority chooses Dauntless.

Teller is one of the few exceptions, and when he hears that his fellow actors all sorted themselves into Dauntless, his brow cocks in disbelief. “Well, they’re all freaking liars. I can tell you right now Ben Lloyd-Hughes, Ben Lamb and Christian [Madsen] are not Dauntless. Look up Ben Lamb on Google Image. He’s riding a horse and doing Shakespeare.” He speaks with the brash authority of a class clown, the type whom kids revere and teachers secretly adore. Thinking for a second, he amends his previous statement. “Jai would be Dauntless. Cos Jai’s a psycho. Theo would probably be Dauntless. But Theo’s a weirdo.” Spoken with fondness, Teller’s declaration hints at the dynamic chemistry among the cast, who, mirroring their characters, have initiated themselves into a rambunctious crew. There’s a special kind of magic here, and the idea of enduring Dauntless hazing (which includes jumping off a speeding train and diving into a deep pit) in order to be a part of it suddenly seems… totally worth it.

The obvious ringleader of the group, Teller identifies himself as Candor, the faction known for honesty, although half of what he says might not technically be true. Gems include: “I’m much more attractive than Theo, so it was weird for him, because he’s used to being the most attractive guy,” and, “I do a reality show. It’s my life. It’s called Miles All The Time. It’s pretty cool.” Not only would this be an awesome show (how can we make that happen?), it would be a ratings hit. The 26-year-old’s star began to rise with his standout performance in The Spectacular Now, and it’s skyrocketing into space thanks to Whiplash, which won both the grand jury prize and the audience award at Sundance this year. With a face like John Cusack and a voice like Danny McBride, Teller has George Clooney levels of charm– and the proclivity for pranks that comes with it.

His co-star, Christian Madsen (one of the “freaking liars” who doesn’t belong in Dauntless), gleefully tells the story of how Teller played a trick on Ben Lloyd-Hughes (another liar) after Veronica Roth visited the set. Teller left balloons and a card with a fake message from Roth for Lloyd-Hughes, who immediately believed that Roth really enjoyed meeting him and wanted him to call her at any time. He texted the number, which actually belonged to Jai Courtney, so the latter responded back with messages as instructed by Teller. The conversation slowly escalated to “Roth” asking Lloyd-Hughes out for a drink, which made him nervous, because the 25-year-old author is married. Delighted by Lloyd-Hughes’ gullibility, Teller wanted to keep the ruse going until the film’s premiere, but Madsen convinced him to take pity on the highly anxious victim and tell him the truth. He took it well, but the best sport was Veronica Roth, who heard the story and made sure to seek out Lloyd-Hughes during her next visit in order to ask, “How ’bout that drink?”

In the film, Lloyd-Hughes plays Will, the most good-natured member of Dauntless, and the actor’s exuberantly warm spirit will only increase fan adoration of the character. He’ll also, no doubt, make certain scenes even more poignant, which can also be said for Madsen in the role of Al, who tragically falls for Tris (Shailene Woodley), the heroine of the story. Tall, introspective and a bit shy, he resembles the character both physically and emotionally. “I connect almost 100% with this guy,” says Madsen, slightly hunched over and looking down at the ground. “Searching,” he softly mutters, “that’s what I see a lot of in Al. Searching to be something… and he doesn’t quite get there.”

Affirming Madsen’s compatibility for the role, Lloyd-Hughes says, “I think Christian was one of the only actors who didn’t read for any other characters.” Madsen, without missing a beat, replies, “Well, except Tris.” His dude-like sense of humor is a surprisingly perfect compliment to that soulful nature, and there’s an earnestness that stems, perhaps, from a previous lack of success. “To be endlessly told no all of the time during this process, and then you get told ‘yes’…” He stops and looks around at the set, almost in disbelief that he is still a part of it. His joy over nabbing the role still hasn’t dissipated since the day he got the news.

“I remember the first person I told was my apartment manager, because I was about to be evicted. So I ran down like three stories with the phone on speaker phone, and I ran over to Joe and I said, ‘Hey man, I’m gonna get my rent paid!’ And he was like, ‘Oh my god, that’s awesome!’ He was behind these bars, going ‘Wooo!'”

Llloyd-Hughes jokingly interjects, “Do you live in a prison?” Madsen: “No, just a weird area of Hollywood.”

These boys are so captivating, I almost forget that they’re not actually playing the romantic lead. That honor goes to Theo James, who seems more than capable of pulling off the brooding good looks and fierce determination of Four, Tris’ initiation instructor and eventual crush. James’ personality is certainly more saucy than Four’s, but they share a fascination with fighting, and James seemed to get even sexier (if that’s possible) when discussing the new fighting style, a blend of Wing Chun and Krav Maga, that the stunt director developed for the film.

Although, according to Shailene Woodley, James is, “Just a giant… dork.” Running her hands through her gorgeous hair (we’re talking Connie Britton levels of luminous), Woodley smiles widely with affection, although I’m pretty sure a stranger off the street would earn the same reaction. Touted on set for being warm (Amy Newbold: “She’s like the world’s nicest person”) and extremely friendly (Teller: “She’ll probably give you all hugs [and say] ‘Bring it in, brother!'”), the star of Divergent is both radiant and calm. She’s also a bit of a hippie. Ansel Elgort, who plays her brother in this film and her love interest in the upcoming The Fault In Our Stars, puts it like this: “Shailene is a health expert. She collects her water from the mountains in California.” He stops and looks down at his snack. “She would be mad at me for eating this kind of yogurt. So we can’t tell her.” And when asked about her favorite place in Chicago, Woodley responds, “The coolest thing I’ve done is the farmer’s market, to be honest.” (Which is exactly what the rest of the cast predicted she would say.)

But don’t let her granola lifestyle fool you– Woodley is just as driven and determined as the heroine she plays, and her career trajectory could reach Jennifer Lawrence levels. Lions Gate and its subsidiary, Summit, are definitely betting on it.

Hoping for another The Hunger Games, the studio has a lot riding on the film’s success, and the poor performance of recent YA adaptations like Mortal Instruments: City of Bones and The Host has cast a foreboding shadow. Then there’s the fans, who worry that this adaptation won’t do justice to their beloved novel.

Fortunately, Divergent is all about confronting fear, so the cast is more than prepared to handle the heavy weight of expectations. “Yeah, there’s some pressure there,” says Zoë Kravitz, who plays Tris’ best friend Christina and is so tiny, it’s obvious why Jai Courtney is looking forward to filming the scene where he dangles her over a chasm. “I think there’s a lot of anxiety going into it, but once you start shooting, you kind of have to let it go, or, you know, you won’t really do a good job. You’ll be too focused on the fear.”

James adds, “Fear isn’t something that no one has, it’s just something that you learn to have an ability to have some control over. And if you have some control over it then you can act, as best you can, in the face of it.”

This incredibly magnetic, deeply talented cast doesn’t just play Dauntless–they are Dauntless. A lot can happen between now and the film’s premiere, but as I walk off the set into the Chicago streets, there’s no doubt in my mind that these crazy kids will make their faction proud.

Sarah, peaking out from an open door of a concrete box-shaped building

Hanging out in a halfway-constructed Abnegation house, which isn’t nearly as cool as Dauntless HQ. Tris definitely made the right choice.

Sarah lives in Austin, and believes there is no such thing as a guilty pleasure, which is part of why she started FYA in 2009. Growing up, she thought she was a Mary Anne, but she's finally starting to accept the fact that she's actually a Kristy.