Once

Once is a novel for younger readers by the Australian writer Morris Gleitzman, published in 2005.

Its narrator is Felix, a Jewish boy who has been hidden in a Catholic orphanage in occupied Poland for over three years and who still believes that his parents, both book-keepers, are alive and about to come for him. When he sees the nuns burning the books in the orphanage library he takes it as a sign and leaves, walking out into a country where notices, gunfire and empty towns are the visible signs of something he has not been told. On the way he finds a girl called Zelda lying unconscious in a burning house with her dead parents, and he takes her with him and protects her from the truth by telling her stories. The novel came from the author's reading about Janusz Korczak and the Warsaw orphanage, and it began a series that follows the same period.

Gleitzman wrote several books about children in the war, and this one was translated into German, French and several other languages.