From The Jacket:
A poignant and ultimately triumphant novel based on the incredible true story of children who braved the formidable danger of guarded, wintry mountain passes in France to escape the Nazis, from the acclaimed author of Courage, My Love.

Southern France, 1942

In a remote corner of France, Jewish refugee Ella Rosenthal has finally found a safe haven. It has been three years since she and her little sister, Hanni, left their parents to flee Nazi Germany, and they have been pursued and adrift in the chaos of war ever since. Now, they shelter among one hundred other young refugees in a derelict castle overseen by the Swiss Red Cross.

Swiss volunteers Rosli Naf and Anne-Marie Piguet uphold a common mission: to protect children in peril. Rosli, a stubborn and resourceful nurse, directs the colony of Chateau de la Hille, and has created a thriving community against all odds. Anne-Marie, raised by Swiss foresters, becomes both caretaker and friend to the children, and she vows to do whatever is necessary to keep them safe.

However, when Germany invades southern France, safeguarding Jewish refugees becomes impossible. Chateau de la Hille faces unrelenting danger, and Rosli and Anne-Marie realize that the only way to protect the eldest of their charges is to smuggle them out of France. Relying on Rosli's fierce will and Anne-Marie's knowledge of secret mountain paths, they plot escape routes through vast Nazi-occupied territory to the distant border. Amid staggering risk, Ella and Hanni embark on a journey that, if successful, could change the course of their lives and grant them a future