Your Sister’s Sister wastes a promising premise and the talents of three good actors, one of whom gives a superb performance.
A young man (Mark Duplass) is grieving a loss and his friend (Emily Blunt) suggests that he spend some time at her family’s remote island getaway cabin. Unbeknownst to them, her sister (Rosemarie Dewitt) is already staying at the cabin. The guy and the sister get drunk on his first night at the cabin, and the friend shows up unannounced the next morning. Each of the three does not know a key fact about the other two. So far so good.
In fact, it’s an excellent dramedy for two-thirds of the movie until the sister bursts out with something like, “I wouldn’t have [spoiler] if I knew that [spoiler]”. At this point, writer-director Lynne Shelton runs out of creativity and resorts to the dreaded musical interlude, in which each of the characters stomp or bike through the rainy Northwest as the music swells to set up an ending that drew loud derisive hoots from the theater audience.
Too bad, because the actors are very good. Mark Duplass plays the smart, talented, underachieving, goofy and sweet big lug usually played by Jason Segal or Seth Rogen. Emily Blunt plays the sarcastic, funny, smart, vulnerable and adorable cutie usually played by Emily Blunt. But Rosemarie Dewitt creates a wholly original and utterly authentic character that looks like a real person, someone we know in real life. All of her actions and reactions are completely authentic, whether she’s drinking way too much tequila, pondering her failed relationship or tasting her own vegan pancakes. Dewitt was also very good as Rachel in Rachel’s Getting Married, and her performance is so good in Your Sister’s Sister that I can’t wait to see her on screen again.