Watch: Trailer For SXSW Smash 'Short Term 12'

At this year's South by Southwest Film Festival there were a lot of high profile movies that only garnered limp shrugs and seesawing hands when you would ask the festival's hardcore how they were. But there was one movie had everyone in rapturous "OMG YOU'VE GOT TO SEE IT" mode, and that movie was "Short Term 12." The affecting drama, written and directed by "I Am Not a Hipster" filmmaker Destin Cretton, won both the Grand Jury Prize award and the Audience Award at SXSW (a rare feat indeed), and based on this trailer, it's easy to see why.

Based on a short film Cretton debuted at Sundance in 2008, "Short Term 12" concerns Grace (Brie Larson, from "21 Jump Street" and this summer's "Spectacular Now"), a supervisor at a foster care facility that specializes in potentially at-risk teens. John Gallagher Jr. plays her longterm boyfriend, who also works at the facility  and Kaitlyn Dever, perhaps best known for a tour de force performance in FX's woefully underrated crime series "Justified" a couple of seasons ago, plays one of the kids.

The trailer crackles with a kind of earthy naturalism, and you can see from the footage how the movie had audiences at SXSW crying and cheering at the same time, although it looks like a pivotal plot point might have been given away (grrr). (Full disclosure: this writer, while attending and covering the festival, missed each and every screening of the movie. It should be noted, however, that Larson gave me a hug at a party later in the week. So there's that.)

"Short Term 12" opens in select theaters on August 23rd. Until then, watch Larson's amazing musical number from "Scott Pilgrim vs. the World."