On an impulse of curiosity, I ventured out for a late-night movie at my neighborhood’s second-run theater. The title, Three Identical Strangers, was intriguing — especially since I knew it was a documentary. But that’s the only thing I knew.

I expected the theater to be quiet and almost empty. After all, this movie isn’t exactly a box office smash. And it’s been playing for weeks. But I was pleasantly surprised. Why were so many people out to see this so late at night, and so late in this movie’s theatrical run? I don’t know, but my guess, now that I’ve seen it, is that word-of-mouth is spreading. From the opening moments to the end, it’s riveting. Everybody stayed, silent and gobsmacked, and then burst into boisterous conversation that continued in the lobby long afterward. It seemed everybody was eager to come to terms with the twists and turns of the story they’d just discovered.

The mystery at the heart of Three Identical Strangers is too good to resist.

I’ll keep my synopsis to one basic paragraph in order to preserve the movie’s surprises:

Three Identical Strangers zooms in on three young men—David Kellman, Eddy Galland, and Bobby Shafran—who, upon discovering one another in 1980, find that there’s a good reason they look alike, sound alike, think alike, and act alike: they’re triplets, separated at birth, and then adopted into families who didn’t know their new sons had brothers.

It’s also about how their story brought them sudden superstardom, success, and challenges beyond anything they could have imagined. (The American television audience, so easily and eagerly entertained, just couldn’t get enough of the fact that all three brothers preferred Marlboro cigarettes, apparently.)

It’s also about differences between the families that raised them. But you’re probably already sensing that things will take a dark turn (several, actually).

You’re going to love this story about Bobby, Eddie, and David. And then you’ll be profoundly unsettled.

And then it does: Troubles emerge not only within the brothers’ seemingly miraculous unity but also in the culture that surrounds them. In fact, the dangers from outside have been working in sinister and stealthy ways from the beginning. You might begin to wonder if this isn’t a documentary at all, but an unnervingly lifelike sci-fi/horror film.

In short, it’s a story about “nature versus nurture”—with a heavy dose of Dr. Ian Malcolm’s rant about the hubris of reckless scientists.

And by the end, it’s become a powerful reinforcement of Rogers’ philosophy.

I’ve been thinking about it for days now. Wardle seems fascinated by some of my favorite questions: How much of who I am is influenced by the basic building blocks I’ve inherited from, say, my grandfathers, both of whom were carpenters? I’m not a carpenter, but when I write, I am preoccupied with architecture. Is there something happening here? Or have I become someone shaped more by teachers, texts, and other outside influences?

Even more so, I’m interested in the relationship between who we become and how much love we’ve received growing up.

You may hear in those words an allusion to another recent documentary: Won’t You Be My Neighbor? Ever since that profoundly affecting movie opened, I’ve been haunted by Fred Roger’s words: “Love is at the root at everything, all learning, all relationships, love or the lack of it.” The insight here isn’t exactly breaking news, but those are just the right words at just the right painful moment for moviegoers like me who are grieving the loss of wisdom in the White House, and the loss of love and compassion as an American priority.

How did I not know this story already? It was in the papers when I was a newspaper-loving ten-year-old; it was the focus of talk shows and news programs that I watched. (Good to see you again, Phil Donohue and Tom Brokaw!) With its charismatic leads, its hilarious twists, and its unsettling true-crime revelations, it’s as movie-worthy as true-life drama gets. But I wouldn’t want to see a full dramatization: There’s just, well… too much drama, and it works because you have to keep reminding yourself: This is real. These aren’t actors. This script hasn’t been revised to sensationalize the truth. And if you tried to depict these developments in a big studio production, with one actor playing three parts, you’d lose the film’s best “special effect”: the physical reality of the triplets themselves.

Triplets on tour: Brotherly love before it turned into brotherly trouble.

No, a documentary was the right choice — and director Tim Wardle has organized his material here brilliantly, his chapters carefully arranged not only for suspense and surprise but also to give weighty attention to the ethical and philosophical questions raised by each new stage of the story. It’s remarkable how much impressively useful and entertaining footage of the actual events exists, and how effectively that footage leads the audience from the initial amazement, laughter, and joy, into sudden alarm, a sinking feeling of suspicion and dismay, and then grief, and, ultimately, well-founded anger.

Chapters are stitched together with modest but effective recreations, something that could so easily have been overdone. At times, the filmmakers underline the Big Moments too heavily in ways that distract from, rather than enhance, the drama; these events are drama enough on their own. (The only moments in the movie that annoyed me were a few occasions when the filmmakers decided to replay key clips, again and again, as if to say “Remember this moment? How do you feel about it now? And… now” )

It’s a minor quibble. I was engaged—enthralled—throughout. The film never felt like it was embellishing the story to sensationalize it. And I was particularly intrigued because of my age: Everything from the footage of TV news and TV talks to the fashions, furniture, cars, and styles reinforced my amazement that these guys were growing up in the same world where I’d grown up, and having such wildly different experiences. I can’t imagine what life was like for any of them, in these bizarre circumstances, and yet their contexts were so familiar that I kept expecting to see my own family members in the background, leaping from my old Polaroids to the screen.

It doesn’t seem likely at first, but this is a story with serious villains.

That makes the inhumanity of the film’s “villains” that much more troubling. When, in the movie, an exasperated man asks how it can be possible for human beings to be so audaciously evil in the mistreatment of parents and children, I wanted to stand up and say “Preach!”

And I’m sure that my anger was increased by my awareness of horrors happening in the world today. This may seem like something of a tangent, but it really isn’t. Three Identical Strangers relies on the fact that a moviegoer’s conscience will recoil at the idea of family members being separated and exploited.

This is a painfully difficult movie to watch in a year when Americans are welcoming the vulnerable, the desperate, the poor, and the war-scarred by breaking up their families, throwing their children in cages, deporting the parents, and doing all of this in the name of “security.”

I used to criticize Hollywood movies for making villains too preposterously heartless, but man… I’ve learned the hard way that there is no such thing. I hope I live to see the great and harrowing documentaries that memorialize the names and faces of those who have written this year’s atrocities into American history, to caution coming generations that seemingly unthinkable sins can be committed right here, right now, by the people all around you. It happened when I was a kid. It’s happening now. If we’re not careful, it will happen to people we know. If we’re not attentive to the Spirit of Compassion, we’ll be complicit in similar sins.

After all, no matter how different we are, based on genetics or upbringing, we all have the potential to set own interests over the well-being of others, the capacity to rationalize our crimes.