Once (novel)

Once is a 2005 BestSeller children's novel by Australian author Morris Gleitzman. It is about a Jewish boy named Felix who lived in Poland and is on a quest to find his book-keeper parents after he sees Nazis burning the books from a Catholic orphanage where he lived for over three years. He finds a girl named Zelda, unconscious in a burning house with her dead parents, and takes her with him. He protects her from confronting her parents' death through storytelling. Although Once is a work of fiction, Gleitzman was inspired by the story of Janusz Korczak, the events of World War II, and Hitler's attempt to exterminate the Jewish population of Europe.

Once was translated into German (Einmal) and was nominated for the 2010 Deutscher Jugendliteraturpreis; it won the 2011 Katholischer Kinder- und Jugendbuchpreis.

The sequels to the book are Then (2009), Now (2010), After (2012), Soon (2015) Maybe (2017), and Always (2021). In chronological order of Felix's life, the books are Once, Then, After, Soon, Maybe, Now, and Always.