Filmed over just twelve days and largely improvised, Your Sister’s Sister stars Mark Duplass as Jack, a man struggling to function a year on from the untimely death of his much loved brother. Jack’s best friend and brother’s ex-girlfriend Iris (Emily Blunt) offers to let Jack stay at her father’s secluded cabin to help clear his head. When he arrives he finds that the cabin is already occupied by Iris’ sister Hannah (Rosemarie DeWitt), a lesbian who has just ended a seven year relationship. Mark and Hannah get to know each other and a bottle of tequila later end up in bed together. When Iris unexpectedly arrives early the next morning a barrage of secrets, lies and half truths comes her way as the other two try to hide what happened the night before.
For a film with a budget which wouldn’t cover Twilight's glitter funds, Your Sister’s Sister looks great. Occasionally you can tell that it was done on the cheap but it never matters. The improvised script and three superb performances help to give the film a realism which propels the drama and comedy forward towards a crescendo, a turning point from which there is no way back. The film’s great selling point though is its story.