What is the theme in Five Chimneys: The Story of Auschwitz by Olga Lengyel?

The will to survive is a theme in the story. Olga finds the will to survive in the admonishments of others that someone must survive to tell the world what happened at the German prison camps. It seem that, until that point, Olga might have given in to the temptation of escape through suicide. A Frenchman who is part of the underground resistance also tells Olga that some must survive in order to tell the story. This man seems to have latched onto this - as well as his role in the prison underground resistance movement - as his own encouragement to survive.