Immortalized by King Lear, the three-sisters drama has been appropriated and embellished countless times by artists as eminent as Anton Chekhov (Three Sisters), Woody Allen (Interiors; Hannah and Her Sisters), and novelist Jane Smiley (A Thousand Acres). Daniel MacIvor’s Marion Bridge is a modest entry into the genre, but it distinguishes itself through an elliptical and refreshingly ascetic approach to family melodrama. In a maritime island town, alcoholic Agnes (an excellent Henny Russell) returns home to help look after her dying mother. Already tending to the hearth are youngest sister Louise (Susan Louise O’Connor), an antisocial couch potato, and middle sibling Theresa (Christa Scott-Reed), a plainclothes nun whose favorite sartorial colors are gray and grayer. Predictably, the sororal trio progresses from awkward non-communication to vindictive bickering to hesitant reconciliation. What’s surprising and most gratifying are all of the big moments that MacIvor doesn’t show us—the offstage mother who communicates solely via Post-its, Agnes’s trips to visit a long-lost relative, and the titular bridge that played a crucial role in each sister’s adolescence. Denying itself many of the obvious means of emotional catharsis, Marion Bridge subsists on small, often trivial scenes that, when taken together, cast a spartan chill that no happy ending can erase.