In 1933, Hannah Arendt fled Berlin to join fellow exiles without means or documents seeking refuge in Paris. Simone de Beauvoir searched for answers to the challenges of a brutal world in Rouen. Ayn Rand, in her Hollywood exile, worked on a novel she believed would reignite the flame of freedom in her adopted homeland. Simone Weil, disillusioned by the outcomes of the Russian Revolution, dedicated all her thoughts and efforts to the plight of the oppressed.

Over the next decade, one of the darkest in European history, these four women, devoted to thought, would develop ideas that would spread across the globe and change the world in the latter half of the century. Wolfram Eilenberger traces the paths of these heroines from Leningrad to New York, and from Spain during the civil war to Nazi-occupied France, to follow the winding trajectories of their destinies.

They faced injustice, lack of freedom, and the incomprehensible violence of their time as women, refugees, activists, and members of the Resistance, but above all as thinkers. By observing the forging of their radical ideas in the relentless crucible of time, we, alongside them, come to believe in the redemptive power of thought.