When Germans overrun Brussels during the First World War, Gabrielle is infuriated to see her newfound happiness shattered. It isn't long before she is faced with an impossible choice. Three decades later, shy and bookish Julienne moves to Brussels with her widowed father at the height of the Nazi occupation and is horrified to witness the city's callous treatment of the Jewis.

In this dual timeline novel inspired by the life of Belgian spy Gabrielle Petit, two very different young women must discover their inner strength to become the heroes their city needs. And when loyalties are tested and decades-old secrets laid bare, their legacies will become entwined forever.