Riley Keough and Shia LaBeouf in American Honey.

Andrea Arnold, director of the excellent Fish Tank back in 2009, delivers her best effort yet with American Honey, the story of Star (Sasha Lane), a teenage girl who leaves her home to join a young tribe of traveling salesmen.

The crew is led by Krystal (Riley Keough) and her lead sales weapon, Jake (Shia LaBeouf). They travel to cities in a van full of runaways and vagabonds, coaxing people in parking lots, truck stops and homes into buying magazine subscriptions. Star pairs off with Jake, who shows her the ropes.

At nearly three hours, the film might be a bit long, but it’s still an engaging enterprise thanks to Lane and LaBeouf, who deliver powerful, and largely improvised, performances. Arnold makes excellent soundtrack choices (Bruce Springsteen, Lady Antebellum, Mazzy Star) that contribute to the film’s convincing road-trip vibe.

The film is filled with unknown faces—in fact, this is Lane’s screen debut—with the nutty LaBeouf being one of the few exceptions. Will Patton also shows up, as a cowboy who picks up Star and gets his barbecue party totally ruined.

American Honey is available via online sources including iTunes and Amazon.com, and will be released on DVD and Blu-ray on Dec. 27.