The extraordinary true story of the sisters who saved each other.

Friedel and Gina, twins and best friends, live happy enough lives. Their world is cycling trips, visits to their father's shops, and first-day-of school excitement.

But this is a world that is about to fall apart.

It is the 1930s, and the Nazis are on the rise across Germany. They hate anyone who is different - anyone who is Jewish.

Friedel and Gina and their family are Jewish, and before long they are forced to journey to Poland, where terrible hardships await in a prison-like ghetto. Soon separated from loved ones, as the Second World War rages around them Friedel and Gina are eventually taken to a Nazi prison camp - a place of danger and fear, where they must do everything they can to survive.

From daring recues to incredible acts of kindness, this is the story of the sisters' love for each other, and of friendships found in the darkest of places.