The room was too small. Einstein went outside where his breath rose in a cloud from his mouth, tangible, as if he were breathing on glass. He imagined writing on the surface of a mirror, drawing one of his gedanken with his finger into his own breath. He imagined a valentine. Lieserl, he wrote across it. He loved Lieserl. He cut the word in half, down the s, with the stroke of his nail. The two halves of the heart opened and closed, beating against each other, faster and faster, like wings, until they split apart and vanished from his mind.