As the Roaring Twenties wind down, Jean-Paul Sartre waits in a Paris café for a first date with Simone de Beauvoir, who never shows. Marlene Dietrich slips away from a loveless marriage to cruise the dive bars of Berlin. The fledgling writer Vladimir Nabokov places a freshly netted butterfly at the end of his wife’s bed. Hannah Arendt, Walter Benjamin, Zelda and Scott, Dalí and Gala, Picasso and his many muses, Henry and June and Anaïs Nin, the entire extended family of Thomas Mann, and a host of other fascinating and famous figures make art and love, write and row, bed and wed and betray. They do not yet know that they, along with millions of others, will soon be forced to contemplate flight—or fight—as the world careens from one global conflict to the next.