Keira Knightley's latest movie will have her partying and acting like a teenager with Chloe Grace Moretz.

In Laggies, a comedy-drama film by Lynn Shelton that debuted at the Sundance Film Festival, the British actress plays a young woman who refuses to grow up, and chooses to party with teenagers instead of making adult decisions.

In the trailer, we see actor Sam Rockwell ask Knightley's actress' character, "Did you hear the one about the grown woman who started hanging out with a bunch of pubescent kids?"

Rockwell plays the father of Chloe Grace Moretz' character, whom Knightley goes to live with for a bit of time as she tries to figure out her life.

Knightley's character is Megan, a young woman drifting through life who attends her 10-year high school reunion and comes to a realization that nothing much has changed. Unexpectedly, Megan's high school boyfriend drops down on one knee to propose to her, and she panics.

She escapes from her boyfriend, telling him that she is off to a retreat, but in truth she moves in with a teenage girl named Annika (Moretz), to live out an adolescent's life. Rockwell plays Annika's father, whom later on, will be Megan's love interest. But will the two figure out how to make adult decisions in order to make the relationship work?

Shelton is best known for her indie movies but in this new film, her directing and storytelling style is a little bit more maintstream. In their review of the film from its screening in the Sundance Film Festival, the Hollywood Reporter says that the film Laggies, "most movie-like movie Shelton has made," given its starry cast and lack of improv. It's also Shelton's first film that she didn't also write, at least in part, herself."
Laggies is written by Andrea Seigel and it co-stars Ellie Kemper and Jeff Garlin. It will open in select theaters on October 24

Watch the Laggies trailer here: