In the afternoons, while the children played outside and worked in the garden, Julien graded their papers. In his free time, he would lie on his bed and read whatever books he could find in the library, preferring Kafka above all others. He’d told Lea to read The Castle, and they’d talked about the book for days. In Kafka’s work, the world made no sense, fates were cast for no reason, men were beasts or insects or they were simply lost, wandering through corridors that led nowhere, beset by those who followed orders no matter how foolish those orders might be. This was not a world in which a person could trust anyone. He’d learned his lesson at the farm and planned never to be defenseless again. He slept with Monsieur Félix’s knife under his pillow, and in the mornings, when he dressed, he kept it tucked into the waistband of his trousers. His philosophy had been formed by his experience. Trust no one, make your own future, love with all your heart.

An apple tree grew outside the window, and below that there was some shrubbery where birds nested. Dozens of swifts were nesting at this time of year, and Julien lay in bed in the early mornings, listening to the birds. The heron had never returned. Julien often felt a wave of despair at this hour, but when he closed his eyes and imagined Lea, he realized this was the way to survive. If he imagined her, he had not lost her.

He became used to his role at Izieu. The teaching itself was fine; and he was good at it, and in many ways it was a relief to be once again immersed in mathematics. He felt close to his father, and to the person he himself had been. Students who were refugees from Germany and Hungary seemed to prefer his class to all others, for the language of math created an equal playing field even for those who fumbled with their French. The couple that ran the school told him he was a natural teacher, and clearly math was his field. And yet, to Julien, making sense out of numbers seemed a false construct. Mathematics was a man-made puzzle that was tugged at and pulled apart until it fit inside a logical mind. Those mysteries his father had spoken of, grand endless numbers that explained the universe, problems thought to be worthy of spending a lifetime studying, seemed preposterous to him.