After 10 or 15 minutes pounding home the key plot threads that Cherie's home life is bad and women don't play rock music (the latter including a cameo from Fast Times' Robert Romanus), Joan (Kristen Stewart) meets record producer Kim Fowley (Michael Shannon) outside a club and manages to sell him on the idea that she plays electric guitar, and that he should help her form an all-girl rock band. Fowley, being unrelentingly resourceful, has a group together almost immediately (Stella Maeve, Scout Taylor-Compton, Alia Shawkat), but the band is still missing that special something extra, so Joan and Kim cruise around looking for potential singers until they settle on 16-year-old Cherie (Dakota Fanning), who jumps at the chance to get away from her boring family. At first, she's unwilling to give Fowley's improvised lyrics to "Cherry Bomb" the naughty twist they need, but eventually he coaxes her wild side out, and both a rock star -- and a train wreck waiting to happen -- are born.

In the central roles, Stewart and Fanning are serviceable and even occasionally good, imbuing the characters with attitude and personality, but the film feels overly concerned with the timeline of events and the factual story of the band to give either of them room to breathe or to indulge in pure character moments. Several scenes are devoted to Fowley and his occasionally funny, anarchic style of band management, and Shannon is excellent most of the time, but these bits still leave the girls standing around while he rants about sex and selling records. Additionally, not only does this take away time from stars like Stewart and Fanning, but it almost completely ousts everyone else: you get hints of Maeve's personality from time to time, but Taylor-Compton's role is basically an irritating, hateful plot device, and I don't think Shawkat has a single line.

One scene in the film notoriously features Jett and Cherie locking lips, but any potential feelings or deeper repercussions of this event are basically ignored, so it feels like a grab to get audiences in the seats rather than a genuine character moment (at least, it does given its status as a focal point of the trailers and marketing, not as a creative choice on Sigismondi's part). The core of the plot is basically centered on eventual Cherie's rise and fall, but Sigismondi is unable or unwilling to let Joan slip out of the movie's spotlight. Instead, she struggles to give equal screen time to Cherie (who is struggling to deal with her alcoholic father and her twin sister Marie) and Joan (who seems like she's waiting for something to happen, as if she's biding her time until a Joan Jett biopic can take over). Marie is played by Riley Keogh, and she and Fanning work up a believable sisterly bond that eases the clunkiness of Cherie's character arc, but on a compressed timeline, the rise seems like a given, and the fall seems pretty short.

Fanning and Stewart share a nice moment at the end of the film, the kind of moment that would've been satisfying if the movie felt weightier while the band was meant to be rocking. Sadly, the supposed musical revolution of Sigismondi's movie feel simple, homogenized, kind of the way you'd expect a movie to feel if they took a story about rock and roll and made a Hollywood movie out of it. The real Runaways might as well be singing to Sigismondi: get down, lady, you've got nothing to lose. The Runaways contains a few tantalizing tastes of something edgier, riskier, out of control, but it's just a taste, and it's not enough.