Director Colin Trevorrow made “Jurassic World” and is currently preparing “Star Wars IX,” but between those two franchise behemoths he’s sandwiched a small film—with a budget of only $10 million, shot in a mere thirty-five days—from a script by Gregg Hurwitz that’s been around for two decades. “The Book of Henry” might be dismissed as nothing more than an odd exercise—a film that begins almost as a sunny Hallmark Hall of Fame depiction of small town family life but turns into something much darker, even tragic. As Trevorrow explained in a recent Dallas interview, however, it was precisely that challenge that attracted him to the script years ago. “It starts out being about one person, and ends up being about someone else. That was something that fascinated me as a storyteller,” he observed.

So Trevorrow, who had enjoyed critical acclaim with his first feature, the independent sci-fi dramedy “Safety Not Guaranteed” in 2012, committed himself to helming “Henry.” But then there arrived an irresistible offer from Steven Spielberg to direct “World.” Trevorrow accepted that challenge, but vowed to return to Hurwitz’s script after finishing the dinosaur epic. He proved as good as his word, and after wrapping the monster 2015 hit he returned to the far more modest project, working with Hurwitz to refine the screenplay.

“The script is twenty years old,” Trevorrow said. “It changed a lot during that time [as Hurwitz rewrote it over the decades], but there are some scenes that stayed exactly the same. The work that I did with Gregg in structuring it, thinking about how to make it work, was largely focused on turning it into something that could be as tonally consistent as possible in a movie that does what it does, something that would allow the audience to accept the shifts and not feel like they were being betrayed. I think that’s the biggest challenge of the movie.”

As Trevorrow observed, “If you come in the middle of this movie, you will have no idea what’s going on, because it changes as much as it does. It is structured like a thriller. When you first watch it, you don’t realize that—because it feels like a family movie in the beginning—but for anyone who watches it again, it’s very carefully laid out. My editor [Kevin Stitt] is an excellent editor of thrillers—he was brought up by Frank Urioste, who was a great editor on “Die Hard,” “Lethal Weapon” and those films—and we talked a lot about whether it would make the tonal shifts less jarring if the rhythm of it felt as if it was propelled toward a suspenseful thriller ending. We tried it many different ways, and ultimately that’s where we landed. The movie moves quickly, and the layers build on top of each other, and by the time you realize what’s going on, it’s changed again and changed again. I hope that’s something audiences will respond well to right now, because I feel we all know the structure of movies; we know it from seeing a thousand of them—you almost find yourself waiting for the turn that you know is inevitable. I don’t think you can do that with this movie.”

Trevorrow added, “You’re planting pieces of information in the audience’s mind that you need them to have as they process and progress. This movie does that in a very delicate way. We cut it for a long time. It took a long time to find our way through these very complex turns, and I knew even in the script stage and the production stage that in the end this movie was going to be made or broken by my editor and me in that time that we spent together.”

“The Book of Henry” centers on a suburban family, a single mother and her two young sons. The older of them, Henry (Jaeden Lierberher), is a genius-level kid who essentially runs the household for his somewhat scatterbrained mom Susan (Naomi Watts) while protecting his smaller brother Peter (Jacob Tremblay). But he’s also concerned about Christina (Maddie Ziegler), the girl who lives next door and seems to be in emotional turmoil, and constructs a complicated plan to help her. When he’s unable to follow through on it, he hopes his mother will do so, and she tries to fulfill his wishes, but only to a point.

“I like to think of it as a coming-of-age movie for a parent,” Trevorrow explained. “We get to see a lot of coming-of-age movies with teenagers, but we don’t want to think about how long it takes for us finally to come of age as a parent. Hopefully you do it soon enough to be able to give [your children] the guidance you want to give them, to teach them how to make the right decisions.”

Watts was drawn to Susan immediately upon reading the script, and Trevorrow was enthusiastic not only about her handling of the role but her interaction with her co-stars. “It was a family,” he said. “When you’re dealing with that kind [short] schedule, no one really has time to experiment; we didn’t even really get to rehearse. We had to go in and try to create something spontaneous and real, and move very quickly through a very complex movie. As a result she became the den mother of our shoot, there to support those kids if I was unable to because I was shooting another scene.”

The casting of Lieberher and Tremblay, on the other hand, was more a matter of serendipity. “I hadn’t seen anything of Jacob’s, because ‘Room’ hadn’t come out yet,” Trevorrow recalled. “I’d seen his audition…and hired him immediately. Jaeden I’d seen in ‘St. Vincent’—I didn’t see ‘Midnight Special’ until we’d shot this movie. I’m very much that way—I’ll see an actor and know immediately that either they’re perfect for what I would love that character to be or just that I want to work with them. Maddie Ziegler is another one. When I watched the videos of her dancing, there’s something about her capability to communicate emotion without speaking, which is what her part required. I knew there was no one else who could have done it. It’s a role played in a series of looks, a series of single shots of her face where she has to show a tremendous amount of pain and fear, so many emotions.”

Trevorrow admits to real uncertainty about taking on the project. “I was never anywhere near as terrified on ‘Jurassic World’ as I was on this movie,” he said. “I had moments of abject fear that I wasn’t going to be able to make it work after a pretty big success. The scope, I can do that. It’s finding an emotional truth in the characters that is hard to manufacture.

“The anxiety came before [the shoot], because ‘Jurassic’ had come out in June, and I started shooting this in the fall, and I had a moment where I was just terrified—what are you doing? Just take your chips and walk out of the casino. Then I steeled up and I did it, because I felt very deeply that this was a story I had to tell, and in the past six or seven months since we finished, I’ve had plenty of those moments again. Is it possible to know how something this different is going to be received? There’s just no guarantee at all.”

Trevorrow believes, though, that “Henry” will find its audience. “This is a movie that not everybody has to love, and yet the people who do, will love it very much,” he opined. “I think there are a lot of people who will be refreshed by something that tells a different kind of story, and does it differently. And I think those people will tell other people. I think it’s a movie for the moment. I’m not looking to project my politics on anything I do, I’m looking to find universal themes and ideas we can all share, values we can all share. And safety for our children is something we all share, the sense that evil exists is something we all share. I think there’s value in that, and I think the audience is going to respond to that.”

Trevorrow also takes comfort in the very modesty of the movie from an economic standpoint. “It doesn’t have to make ‘Jurassic World’ money at all,” he said with a smile. “It can make ‘Jurassic World’ first two showings money, and they’d be thrilled.”

Asked whether he’d like to continue alternate big=budget films with more intimate ones, Trevorrow simply responded, “I would like to continue challenging myself and being afraid of what I’m doing, and pushing myself to try to do something that could go horribly wrong. This is a movie that could have gone way off the rails, and there may be some people who feel that it does.” But he added. “I’m very confident that it’s a cohesive structure and that it sticks to landing.”