The runaways: "Electrick Children"

For Rachel (Julia Garner), the young heroine of Rebecca Thomas's post-Martha Marcy... indie drama Electrick Children, the sixteenth year will be one of discovery. In this, she is not unusual - but as Rachel's been cloistered since birth in a Mormon community somewhere in the Utah desert, the process of revelation will take two unlikely forms. Firstly, there's the cassette tape she's found, upon which someone's recorded The Nerves' 1976 single "Hanging on the Telephone", the likes of which she's never heard before; secondly, there's the news that - despite her apparent innocence in matters sexual - she's fallen pregnant. For Rachel, this is a miracle, an act of God; her elders (Billy Zane and Cynthia Watros) are notably less enthusiastic about this announcement, and proceed to do their best to lock their charge down. Whereupon Rachel steals daddy's (possibly the daddy's) truck and flees into the backstreets of nearby Salt Lake City, where - this being the early 1990s - she and her errant brother Will (Liam Aiken) fall in with a gigging grunge band, and are introduced to the delights of not only guitar music, but cellphones, skinnydipping and pizza.

In such synoptic form, Electrick Children sounds inherently preposterous: not for nothing does the poster attempt to frame it as "Witness meets Almost Famous", a combination that sounds about as likely to cohere as, let's say, Schindler's List meets Space Chimps. Thomas's trick is not to smash these contrasting worlds together, but introduce them gently and sensitively: she takes it moment by moment, scene by scene, determining to show us through Rachel's eyes - and the engaging Garner's lucid and intuitive performance - what this culture clash might have looked and felt like, in the event that it did happen. Perhaps inevitably, these two tribes emerge as not so diametrically opposed after all. Rachel's politesse is met with amused fascination and respect by her hosts (if nothing else, you sense they spy a possible concept album in the encounter); both are outsiders, on the run from their elders; both have been made queasy by conformity, and yet neither faction is quite certain where they're heading in life. Thomas's finale depends on diverse characters happening across one another, and responding altogether more coolly to events than they might perhaps have done in real life, but this remains a nicely handled and acted debut, one that never seeks to romanticise its runaways' adventures: Will's first attempt at skateboarding results in a broken arm, and it's a smart choice that the version of "Hanging on the Telephone" that awakens Rachel's curiosity isn't the glowingly produced Blondie version, but the kind of pub rock that might only change your life if you were young and impressionable, and had never heard music before.

Electrick Children is in selected cinemas nationwide.