An almost hypnotic sense of naturalism draws you into “Your Sister's Sister,” an intimate comic-drama about three people who find their lives intertwined in sudden and unexpected ways.
Writer-director Lynn Shelton, who made the possibility of gay porn between straight best friends seem logical if not downright inevitable in 2009's “Humpday,” once again employs her preferred tactic of having her actors collaborate on developing their characters and improvising their dialogue. (The stars get a “creative consultant” credit.) The result is appealingly, believably imperfect. And although the end feels a bit too tidy by comparison — despite a final shot that's intentionally ambiguous — it also has an emotional impact that will sneak up on you.
That's thanks to Mark Duplass, who also co-starred in “Humpday,” making an understated final plea that's sweetly heartbreaking. This is probably his best work yet, his most mature and deeply felt. And he's been everywhere in the past year or so between this, “Safety Not Guaranteed,” the FX series “The League” and his own directing efforts with his brother, Jay, like “Jeff, Who Lives at Home.”
Here, Duplass stars as Jack, who's still feeling shattered a year after the death of his brother. Jack's best friend, Iris (Emily Blunt), suggests that he get away for a while on his own by visiting her family's remote cabin on an island off the Washington coast. (Shelton shot “Your Sister's Sister” on the San Juan Islands, and the quiet, jagged beauty of the place adds to the sense of isolation, to the idea that anything could happen between these people.)
‘Your Sister's Sister'
Starring: Emily Blunt, Rosemarie DeWitt, Mark Duplass, Mike Birbiglia. (Language and some sexual content)