If Bobby (Lonnie Chavis) and Kevin (Ezra Dewey) are feeling trapped at the start of “The Boy Behind the Door,” they have no idea how bad things are going to get. Wondering aloud leaving town without yet being old enough to drive, the two are preparing for a Little League game when an errant throw while playing catch sends Kevin running down a hill, never to return. You already know that the two boys see each other again in David Charbonier and Justin Powell’s agreeably nasty feature debut because this early scene is a flashback to better times after the film opens inside the back of a trunk where they’ve been bound in duct tape without a clue where they’ve been taken.

Initially, the age of the prepubescent protagonists is used to shock when they’re thrown into a thriller very much for adults, but as “The Boy Behind the Door” wears on, Charbonier and Powell cleverly turn that perspective to their advantage in other ways as Bobby and Kevin draw on their youthful imagination to attempt to make their escape and the audience is put in their shoes of not knowing what to expect from the world around them. The co-writer/directors wisely decline to give the villains much definition, only on camera as much as they need to be, making them more dangerous as a looming threat, and sharing little about their motives, though it’s inferred they might be in child trafficking. Anchored firmly in the POV of the kid the film is following at the time — primarily Bobby, when Kevin has already been locked away somewhere in the house while he finds his way to break free of the car — Charbonier, Powell and cinematographer Julián Estrada muscularly manuever around the cold manor as the boys start to figure things out for themselves, gradually laying the groundwork for them to outwit their captors as the filmmakers outwit an audience that thinks they’ve seen this film before.

Despite a joke being made about Bobby and Kevin contemplating how to hook up a rotary phone, you wouldn’t know this is an era with cell service when cop cars look like they’re from the 1980s and time becomes one expositional ambiguity of many that the film plays with that keeps you on your toes. The fact that Charbonier and Powell aren’t exactly forthcoming with answers doesn’t mean they don’t have them and the way they build a world from the ground up that makes complete sense as you get more familiar with it is impressive, as is how much the directing duo trust what they can leave unknown in silences and lurking just off camera to build suspense. In an era of predictable jump scares and overwrought evocations of evil, “The Boy Behind the Door” will make you feel like a kid again in its thrills and chills.

“The Boy Behind the Door” will screen virtually at AFI Fest from October 17th-19th, available for a 48-hour window once you press play.