As true as a documentary can get, Mrs B. reveals and conceals in equal measure. It shows the reality of a woman who left everything behind, including her husband and two sons, to seek a better life, and who, in some ways, has known the worst. And speaking of “the worst”, the eponymous Mrs B. (whose name is never revealed) knows everything there is to know about the trafficking of North Koreans. Over a decade, Mrs. B. has learned the tricks of the trade herself and runs a trafficking business from her small farmhouse in northern China. She knows everything about crossing frontiers, particularly one: the icy Tumen River that separates North Korea from China, through which she brings her compatriots. We never get to learn how she feels about it. Then, to reunite with her own Korean family, she takes a long, perilous trek through China and Thailand.