Four stunning titles have been shortlisted for the 2009 Guardian children's fiction prize, reflecting both the breadth of writing for children and young adults and an optimism about the power of story to inform and guide. Though the four are widely varied in context, each is the hopeful story of an individual's journey - one which reveals how they have been made, and sometimes unmade, by the society they come from. In different ways, and set in different times, all reflect on how the present is affected by the baggage an individual carries with them from before the start of the story, while also showing that everyone can influence what happens next.

To succeed in writing about the Holocaust with a light touch is rare indeed, but Morris Gleitzman has done so in two novels - first Once and now Then. Felix and Zelda jump off the train that is carrying them to a Nazi death camp. Neither has any family remaining and, for different reasons, both are at risk. Felix devises a plan that includes pretending they are not who they are and finding new parents who will keep them safe. The plan is a good one but hard to achieve. Fortunately, Felix and Zelda meet much kindness in their search for new lives - signs of humanity which make a welcome contrast to scenes of horrifying cruelty. Writing without sentimentality but nonetheless through the eyes of a child, Gleitzman retains something of a child's innocence in his worldview and so allows individual hope to be kept alive despite the suffering witnessed.

 The winner of the prize will be announced on Thursday 8 October