On the night of the Tiananmen Square massacre, a woman gives birth alone in a Beijing hospital. So begins the slow unravelling of Su Lan: a woman determined to remake herself, an ambitious physicist and ambivalent mother who becomes consumed by her research into disproving the irreversibility of time. Following Su Lan's sudden death, her daughter Liya travels from the US to China to try to understand the silences and ghosts her mother left behind. Adrift in a country she doesn't know, Liya begins to piece together how her mother's obsessive desire to erase her own past has marked the lives of those around her, and Liya's own.