Nella Larsen’s compact, potent 1929 novel tells the story of two girlhood friends from Chicago who reconnect later in life. Both are Black, but one has taken great pains to pass as white—she’s so successful at it that she’s in danger of erasing her true self. This is the source material Rebecca Hall chose for her 2021 filmmaking debut, and the resulting movie is both sturdy and supple, a reflection not just on racial identity but on the ways all human beings long, in some way, to fit in,