The actress is going 'Big.'

Age-swap movies have always had a place in the film canon. From Big to 13 Going on 30, feel-good stories about self-acceptance have warmed the hearts of audiences for decades, with many going on to become ageless classics. 

Now the sub-genre is exploring a narrative seldom told on-screen… the experience of a woman over 70. Mack & Rita follows a disenchanted 30-year-old influencer named Mack (You's Elizabeth Lail), who feels disconnected from her youth. 

"I grew up always feeling like I was an older woman trapped in the body of a little girl," Mack says in the promo. "I did my darndest to keep my inner old gal to myself." 

But during a bachelorette party in Palm Springs, she stumbles into a past life regression session (led by Red Rocket's Simon Rex), and when she emerges, she's stunned to find her inner old gal unleashed, literally, as she's turned into her 70-year-old self (played by Diane Keaton). 

Diane Keaton is 30 going on 70 in new Mack & Rita trailer
Diane Keaton in 'Mack & Rita'
| Credit: Gravitas Premiere

Directed by The Morning Show helmer Katie Aselton, the film follows Mack as she rebrands herself as Glamy Granny "Aunt Rita," and embraces how she's always felt inside. Freed from others' expectations, Rita finds herself an unlikely social media star and at the center of a budding romance with Mack's dog sitter (Schitt's Creek Dustin Milligan). 

But as she finally comes into her own, will the physical transformation be as permanent as her inner one? 

Rounding out the cast are Taylour Paige (Zola), Loretta Devine (Family Reunion), Amy Hill (50 First Dates), and Lois Smith (Lady Bird), Wendie Malick, Patti Harrison, Martin Short, Addie Weyrich, Aimee Carrero, and Nicole Byer.

Mack & Rita is set to turn the clock forward in theaters on August 12. 

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