There's a new student at the local high school, and she of the frosted tips has certainly caught the eye of Beaver (Daniel Webber). Kat (Eliza Taylor) is initially standoffish but warms to the young man after he presents an opportunity to enter the inner circle of Wyatt (Pablo Schreiber), an Iraq vet and local heroin supplier. Sure enough, before you can say "narc," Kat's flimsy narrative begins to unravel, putting both her and the hapless Beaver in peril.
Writer-director Ross' résumé is heavy on reality shows, and his handheld approach contributes to Thumper's gritty aesthetic. The film also is buoyed by Schreiber's intensity (the ease with which Wyatt turns from doting father to potential murderer is chilling). Wyatt is surprisingly layered, pushed to his chosen career beyond the usual "get rich or die tryin'" motivation. Lena Headey gets in on the action as a police handler who's increasingly impatient with Kat's reluctance to bring any of the teens to justice.
And while Kat does the minimum to keep us engaged, Beaver provides the story's moral focus. Not yet hardened by the streets, and hustling only to get his special-needs little brother out of their abusive home, Beaver is who we sympathize with, and about whom we fear the worst.