This highly engaging analysis of the contemporary, global social and political landscape of trans antagonisms draws specific attention to "gender-critical” mobilizations of Simone de Beauvoir's account of becoming a woman in The Second Sex to advance and justify trans exclusionary positions. Through a careful examination and application of Beauvoir's philosophical and political commitments, this book compellingly explores the significance of her notion of becoming as not only affirmative of trans women, but also as an ethical demand to affirm trans possibilities.