Starring Katherine Waterston and John Leguizamo. Rated 18A.

This study in kid culture should not be confused with The Baby-Sitters Club—unless, of course, you care to picture the girls of Ann Martin’s preteen books as almost grown and turning tricks for extra money.

Katherine Waterston—daughter of Sam, and almost as tall—plays Shirley, a high-school senior looking for ways to pay for Ivy League college when she runs into a literally sticky situation with her new employer, Michael (John Leguizamo), whose midlife crisis takes the form of slipping her overtime bucks for special attention.

To be fair, it’s Shirley’s crush on him that sets things in motion. And anyway, that shrewish wife of his (Sex and the City’s Cynthia Nixon) doesn’t understand him at all. Anyway, it’s not long before Shirley slips this secret to her cynical best pal (Lauren Birkell), who takes the news as a swell business proposal. Next thing you know, Shirl is snagging 20 percent from a nice little stable of high-school ’hos. As in any wildcatting operation, though, there’s always the danger of independent contractors trying to undermine pioneers taking most of the risk.

This directorial debut for David Ross, who previously hung around another bunch of schoolgirls to write The Woods, starts out by saying some fairly pithy things about the mercantile spirit that is currently shoving everything in America into the marketplace. But about halfway into the proceedings, after Michael foolishly lets his crass coworker (House’s Andy Comeau) know about the newest neighbourhood service, the film spins out of control. By the time our former straight-arrow student (with compulsive tendencies) starts trashing the school at night, you really have to wonder what she, and the filmmaker, are on about.

Lots of faces familiar from episodic TV show up in small roles, and it’s cool the way Ross pulls back from the melodramatic brink to toss in unexpected developments. But in the end, the empathic director is let down by the scattershot writer. That they are the same person doesn’t make it any easier for him, or us.