It is the Autumn of 1943. Italy signs the armistice that will take it out of the war, and slides into chaos. In Florence, two sisters, Isabella and Caterina Cammaccio, find themselves surrounded by terror and death. As the Allied advance stalls in the south, Italy is trapped under the heel of a brutal Nazi occupation. Determined to take on not only the Nazis, but also the newly resurgent Fascists, bands of Partisans rise up. Almost all of them are young. Many of them are women. They have little to rely on except ingenuity, determination, and courage.

Thrust headlong into the unknown, Isabella and Caterina will test their wits and deepest beliefs as never before. As the winter grinds on, they will be forced to make the most important decisions of their lives. Their choices will reverberate for decades.

In the present day, Alessandro Pallioti, one of Florence's most senior policemen, would not normally oversee a murder investigation. He agrees only because the victim – an old man found dead in his apartment – was once a hero, one of the few surviving Partisans who took part in the city's liberation in 1944.

The memories of old heroes should be nothing more than a diversion. But, as the case begins to unravel, Pallioti finds himself first pulled backwards in time, then racing against it, working to uncover a crime lost in the twilight of war the consequences of which are as deadly today as they were over sixty years ago.