In "Your Sister's Sister," Duplass plays Jack, an unemployed Seattle guy who's having the worst year of his life, after his well-regarded brother Tom died. Jack's best friend, Iris (Emily Blunt), who dated Tom for a time, sees how bad Jack's year has been, so she proposes a solution: letting him use her empty family cabin in the San Juan Islands for some alone time.
Iris' plan hits a snag when Jack arrives at the cabin to find her sister Hannah (Rosemarie DeWitt) already staying there. Hannah has just broken up with Pam, her girlfriend of seven years, and is seeking solace in a tequila bottle. Jack joins her for a few shots, and the evening and the following few days, as Iris arrives unannounced takes some serious and unexpected turns.
Shelton, the film's writer and director, lists her cast (along with comedian Mike Birbiglia, who has a key scene at the beginning of the film) in the credits as "creative consultants," which appears to mean they brought their own ideas to the semi-improvised script. They collaborate on characters who are emotionally complex and true-to-life, reacting to revelations and there is plenty revealed as the story goes on with honesty and humanity.
The three leads pinball off each other charmingly, capturing the prickly dynamics of relationships between best friends, between sisters, and between strangers with an undeniable link. The performances mesh neatly, too, with Duplass capturing Jack's self-destructive grief, DeWitt (the Rachel of "Rachel Getting Married") nailing Hannah's prickly personality, and Blunt finding the tentative yearning in Iris.
Even when Shelton cops out in the finale, with a resolution that's just a bit too pat, the actors make it feel authentic. I found myself forgiving Shelton for wanting her characters to come out on top in the end because I'm sure she grew as fond of them as I did.
'Your Sister's Sister'
Three characters in one cabin, in a thoughtful and authentic comedy-drama about family and other relationships.
Where • Broadway Centre Cinemas.
When • Opens Friday, June 29.
Rating • R for language and some sexual content.
Running time • 90 minutes.