‘Cop Car’ more than just a B movie

Kevin Bacon plays a villainous sheriff in the new thriller.

The new thriller “Cop Car” offers a textbook illustration of the late Roger Ebert’s notion that a movie “is not about what it’s about but how it’s about it.”

There couldn’t be a simpler premise: two kids (James Freedson-Jackson, Hays Wellford) — come upon an abandoned police car and take it for a joyride, much to the chagrin of the villainous sheriff (Kevin Bacon), who happened to have stored a man in the trunk. The sheriff needs that car back and isn’t above harming some adolescents to get it.

But director Jon Watts, who co-wrote the script with Christopher D. Ford, brings an artist’s touch to the B-picture exterior. He aspires to more than cheap exploitation.

There’s relentless tension, crafted through a steady build-up of suspenseful moments and real-time scenes that breathe at longer-than-expected lengths, amid imagery that emphasizes the primal nature of the rural, summer Colorado landscape.

It’s a visceral achievement that serves as a heady metaphor for the looming specter of adulthood, with its tough choices and moral compromises. Watts is less interested in filling in the narrative blanks, explaining exactly what led the sheriff to this spot or why these kids have apparently fled their homes, and more committed to creating a mood of looming darkness, a coming storm of consequences sweeping over the kids’ sunny day.

Bacon and his young co-stars are uniformly terrific, committed to underplaying amid what could have been the perfect excuse to descend into over-the-top fantasy.

The movie can’t totally escape the thin conceit; it goes on too long and occasionally succumbs to the sort of convolutions that Watts painstakingly fights against.

But it’s a fine piece of pure, small-scale genre entertainment, a film made with the highest attention to detail and the all-important awareness that so much of what makes a movie work unfolds below the surface of its plot.

“Cop Car” Directed by Jon Watts. Starring Kevin Bacon, James Freedson-Jackson, Hays Wellford. Rated R. Playing at AMC Village 7

Robert Levin