PHOTO BY TEMMA HANKIN / SCREEN GEMS

Within the incredibly specific micro-genre of computer-screen thrillers — movies that unfold entirely on a crowded laptop screen, with ample use of FaceTime — “Missing” is a fine example of both the benefits and the drawbacks. Its format is used to season and complicate a fairly straightforward narrative, to great effect — even if its payoff can’t quite match its mystery.

If you don’t know what this tiny movement is all about, don’t feel bad; it’s a blip in the overall cinema landscape with only a few notable examples (“Friend Request,” “Searching” and “Host” are the most successful). The movie screen is, with ample cheating, turned into a computer screen; footage is filmed through webcam-enabled apps, and plenty of the drama comes from uncovering details in email accounts and GPS history.

It’s a little odd to see on the big screen — these films, and these films alone, are probably best viewed on a device — but it’s easy to acclimate to the concept. (You’ll probably find yourself reaching for the keyboard instinctively at one point or another.) And while it’s not likely to become a dominant mode, “Missing” demonstrates how to use it effectively.

Like many 18-year-olds, June (Storm Reid) is fed up with the overprotective nature of her mother, Grace (Nia Long). She can barely conceal her glee when Grace and her boyfriend Kevin (Ken Leung) take an overseas trip; when neither grown-up turns up at the airport a week later, though, she panics.

With the aid of a remotely hired helper on the ground and some sophisticated password guessing, Grace — who, for the aid of the audience, seems pathologically determined to keep the webcam trained on her face and running at all times — investigates the disappearance. When she unearths footage of her mother and her beau being kidnapped, an international incident is born.

The twists in “Missing,” which was written and directed by Nicholas D. Johnson and Will Merrick in their freshman feature, are surprising and effective — and the gimmick makes the most of them. These are the sort of reveals that might feel pulpy or procedural if presented normally; there’s a thrill, though, in watching June make a realization, then plum the depths of her internet connection in a desperate rush to find evidence.

“Missing” peaks early, with a dramatic scene of terror — captured at bizarre angles through a smart watch — serving as the narrative climax. There are more twists to come, and an ending that tends back toward the pedestrian. Most of the way, though, scrolling through June’s device is far more intriguing than staring at your own.

My Rating: 6/10

“Missing” is now playing in theaters.