Three male explorers discover an isolated society made up only of women who have sustained themselves for generations without men. The strangers encounter a highly organized, cooperative commonwealth that practices communal child-rearing, scientific agriculture, public health, and noncompetitive education, and whose reproduction occurs by parthenogenesis. Over extended contact the visitors test and compare their assumptions about gender, marriage, and power with a social order that minimizes hierarchy, war, and material scarcity; some men adjust to the society’s values while others resist, leading to strained relations and the visitors’ eventual departure. The narrative explores alternatives to patriarchy, redefines motherhood as a civic responsibility, and considers social reform.