In Once, Felix escapes from an orphanage only to learn that Poland is a dangerous place for a Jewish boy on his own. He manages to look after himself and another young orphan, Zelda, until they are taken under the protection of a kind Polish dentist. But when the Nazis uncover their hiding place, Felix and Zelda must once again run for their lives...

In Then, Felix and Zelda have escaped from the Nazis, but how long can they survive when there are so many people ready to hand them over for a reward? Thanks to the courage of a kind, brave woman they are able to live for a while in the open, but Felix knows it's only a matter of time before he's identified as a Jew, which would mean death for them all. Even though he promised Zelda he would never leave, he knows he has to, before it's too late...