'Searching' review: John Cho's warm performance brightens this high-tech thriller 

The medium is the movie in “Searching,” a missing-daughter mystery in high-tech garb. If it didn’t unfold entirely on laptop and smartphone screens, there wouldn’t be a whole lot to recommend “Searching,” whose plot is about as contrived and corny as an old TV detective show. Still, this Sundance Audience Award winner pushes its all-online concept as far as it can go, and sometimes further, often with entertaining results. “Searching” also holds on to its humanity thanks to John Cho in a warm, empathetic performance as a desperate dad.

Cho plays David Kim, a single father in San Jose, California, whose life story we learn in an opening montage of computer photos and videos — a jpeg version of Pixar’s “Up.” David’s wife died of lymphoma, leaving an emotional gap in the household. David's daughter, Margot (Michelle La), is now 16 and has her own life: study group, camping trips, a roster of online “friends.” When Margot fails to come home one night, however, David realizes just how little he knows about her. So he goes to the one place where a teenager would truly bare her soul: her laptop.

It’s a sudden and telling segue from David’s computer, which is all appointment calendars and family keepsakes, to Margot’s, a foreign and intimidating land of avatars, trolls and randoms who speak in cyber-signifiers. Hacking passwords and scouring search histories, David snoops through the modern-day equivalent of a locked diary. Helping via Skype is police detective Rosemary Vick (Debra Messing), a mother herself. "You don't always know your kid," she tells him.

Writer-director Aneesh Chaganty, a former Google content creator, and co-writer Sev Ohanian (Chaganty’s mentor at USC’s film school) segue fairly smoothly from screen to screen, and even the clumsier transitions have a certain charm. When David takes a late-night drive to a mysterious location, for instance, he’s represented by a moving arrow on a map app — not unlike what old adventure films used to do with dotted lines. If some of these screen ploys feel forced, the filmmakers’ determination to never stray from their concept is impressive.

Despite the many corny moments in “Searching,” Cho keeps earning our sympathy as a father who refuses to believe the worst about his child. “Searching” may be mostly a cyber-gimmick, but it still has a human heart.