After the death of her life-long writing partner and friend Jean-Paul Sartre, feminist philosopher Simone de Beauvoir (Castor), author of The Second Sex, decides to adopt her mid-life companion Sylvie Le Bon as her daughter. When Sylvie refuses to agree to the adoption, Beauvoir must persuade her to change her mind. If Sylvie won't agree to the adoption, Beauvoir will have to leave Paris and live with her sister in Alsace if she becomes sick and cannot care for herself. Informed by biographies of Beauvoir and interviews with Le Bon, the play imagines and interprets this one moment in the women's 26-year relationship and stages other important in the family life they created together long before such a family was recognized legally anywhere in the world.