Sometimes in life, the greatest blows we take come from those who are supposed to be the closest to us. In a nutshell, that’s what Tracy Letts explored in his Tony- and Pulitzer-winning play, August: Osage County, now adapted by the author from a three-hour play into a two-hour film.

The Weston family is a dark one. Patriarch Beverly is a drunk, and his wife, Violet, pops pills like they’re candy. Eldest daughter Barbara is separated from her husband, middle child Ivy is involved in an inappropriate relationship, and youngest daughter Karen runs from man to man across the country. When they’re brought together following Beverly’s disappearance, barely-covered tensions quickly turn this unplanned family reunion into a verbal – and occasionally physical – war zone.

August: Osage County is a verbally-driven film, and its success or failure depends on the cast assembled. The film’s greatest strength is in how many parts of the large ensemble work. The two biggest names, Meryl Streep and Julia Roberts, get the juiciest roles as Violet and Barbara, respectively. Streep is Streep, so she’s excellent as expected, but Roberts manages to actually top Streep’s performance. Roberts sheds her movie-star persona and turns in her darkest performance since Closer a decade ago.

Of the other cast members, three turn in performances that are worth mention. Margo Martindale and Chris Cooper play Violet’s sister Mattie Fae and her husband Charlie, respectively, and while they provide a lot of comic relief, each is able to switch instantly to some dramatic moments. Julianne Nicholson, meanwhile, delivers the most heartbreaking performance here. As the daughter still trapped in her mother’s world, there’s a faint glimmer of hope for an escape she displays that’s decimated by the film’s end.

If there’s one part of the film I have a small issue with, it’s the direction. Director John Wells makes a lot of obvious, safe choices here. He’s content to let the script and the actors do the heavy lifting. Now, when your script and cast are this strong, it’s easier to forgive, but I do have to wonder what a stronger director would’ve brought to the film.

That’s a minor nitpick, though. Thanks to Letts’ work and a set of strong performances, August: Osage County delivers a sharp, brutal look into the damage that can be created in a family. Highly recommended.