Set in the days before and immediately after England’s 2005 transit bombings, London River scales the tragedy down to two parents searching for missing college-age children: Elisabeth (Brenda Blethyn) is a Guernsey homesteader in sporadic touch with her daughter; French-African Ousmane (Sotigui Kouyaté) left his son in early childhood. Both arrive in London—as many parents might under similar circumstances—with little idea of how or where their children are living. Following the clamor of his World War II combat drama Days of Glory, director Rachid Bouchareb brings a measured hand to this intimate, occasionally overdetermined sketch of the aloneness at the center of our global confluence. Suspicious of his spectacular dreads and spidery limbs, Elisabeth ices out Ousmane when they meet on the bureaucratic trail, even after discovering that their children were lovers who lived and studied Arabic together. The slow trudge toward seemingly inevitable news lags in the middle, with Elisabeth’s casual provincial bigotry and Ousmane’s deliberate opacity sapping narrative tension as they make their grim rounds from police stations to hospitals to morgues. It is the pair’s eventual connection, though, that highlights their mutual desolation, delivering the story from patchy, multiculti moralizing to an ending of rough, personal grace.