When Liv finds a secret box from her grandmother's childhood she uncovers an extraordinary war-time story of bravery, betrayal and daring defiance. A story that will change Liv and her family forever...

Holland, 1942. The world is at war and as the Nazis' power grows, Jewish families are in terrible danger. Twelve-year-old Mila and her older sister Hannie are sent to live with a family in another city with new identities and the strict instruction not to tell anyone that they are Jewish.

Hannie, determined to fight back, is swept into the Dutch resistance as an undercover agent: Code Name Kingfisher. And though Mila does her best to make friends and keep out of trouble, there is danger at every turn and the sisters are soon left questioning who they can trust...