“Are you having fun?” Nick (Alex Pettyfer) asks his younger brother Sam (James Freedson-Jackson) as they sit in a lonely roadside diner deep into the night during an early scene in “The Strange Ones,” with the words hanging in the air as Sam is slow to respond. It’s a surprisingly loaded question since Sam doesn’t know how to feel – the two are running away from something unclear and the late night excursion is far less of an escape than an entrapment as it becomes clear that both are using the conversation to break free of their own thoughts. Still, while neither Sam nor Nick may be having a good time, it is quite likely that you will in Christopher Radcliff and Lauren Wolkstein’s mesmerizing feature debut that invites the audience to piece together a mystery at the same speed as its characters.

“The Strange Ones” is an expansion of Radcliff and Wolkstein’s short film of the same name in 2011 and like Wolkstein’s celebrated run of short films (chief among them, “Social Butterfly,” which was edited by Radcliff), it is a movie perfectly engineered to seduce. It teases what its about, it whispers in your ear with diegetic sound often building into a rhythm that entrances, it intoxicates with splashes of colors that hold off the darkness, and it knows exactly how to hold you in its thrall. Yet nothing about it is remotely romantic as a succession of images hinting at past trauma floods the screen in its opening scene to place you firmly in the mind of the barely pubescent Sam, who has trouble making sense of where he and his brother are headed. With Nick headstrong in his desire to get the hell out of Dodge, Sam is skeptical as they find a place to stay – for free, no less – and the boy jeopardizes their good fortune by asking the kindly motel employee who takes them in if she really knows who she’s doing a favor for.

She doesn’t, but more to the point, you don’t either, which gives “The Strange Ones” its considerable suspense. By the time the film allows you to know Nick and Sam well enough to be able to surmise what they’re up to, a more conventional thriller about two brothers on the run gives way to a potboiler as intellectually gripping in its quiet moments as when it starts taking its twists and turns. Radcliff and Wolkstein parse out clues about the past with surgical precision in crafting enigmatic yet intriguing exchanges between the characters, but equally impressive is the skill with which the two structure the film as a whole, with Sam’s abstract memories gradually coming into focus to give shape to the past and inform his present behavior. Through cinematographer Todd Banhazl’s slow, deliberate zooms, one can extrapolate the vastness of the world that Sam feels that he can get swallowed up by and Nick hopes to disappear into while their assumption of an ever-present eye watching them intently wears on them.

It isn’t just how  “The Strange Ones” is framed that’s so compelling, but how Pettyfer and Freedson-Jackson both hold their own on screen, no small task when the weight of the film is largely on their shoulders. Freedson-Jackson gives a captivating performance as Sam, having a comprehension of certain things beyond his years but frustrated by his inability to express them maturely, but strangely the revelation may be the more well-known Pettyfer, who is nearly unrecognizable from his run of heartthrob parts in films such as “Beastly” and “Magic Mike.” The actor undergoes a burly physical transformation for the part, but in playing a thoroughly broken soul, he subverts his charisma into something tragic, as if he’s beholden to the image other people have of him and can’t risk exposing himself as being any different. He fits right into “The Strange Ones,” [where] looks frequently can be deceiving, but there’s one thing you can be sure of — Wolkstein and Radcliff have done something special here.

“The Strange Ones” does not yet have U.S. distribution. It will play at SXSW once more on March 15th at the Alamo Lamar at 8:30 pm.