Content Warning: This section contains descriptions of antisemitism and the Holocaust, including human rights violations, severe abuse, violence, genocide, and gruesome death.

Leo is one of the novel’s three protagonists and the only survivor. Like his friends, his story begins in Vienna on his ninth birthday. It is revealed in the story’s conclusion that Leo is telling his own story in hindsight as he approaches the end of his life. When Leo is nine, he is still innocent and full of excitement. Riding the Ferris wheel is the greatest thrill, and even in his nineties, he still considers that day to be the best day of his life. The day could not have been complete without his two best friends, Max and Leo, and his papa, whom the young Leo deeply admires. As the political currents begin to change around him, Leo starts to suspect that something is wrong with society, and this sentiment is confirmed when he sees the mood shift in his parents. When Elsa later announces that her family is leaving the country to escape impending danger, Leo instinctively knows that her warnings are accurate.

Leo and the other Jewish students at his school are singled out and degraded when the Anschluss occurs and Austria comes under Hitler’s rule.