This book revisits two characters from my Frontline Nurses trilogy. At the end of the last book in that series Leonora and Sasha (Count Alexander Malkovic) have been reunited with their two-year-old daughter, Alexandra. A Call to Courage opens twenty years later. Alix has had a violent quarrel with her father, who wants her to marry Nikola, to cement the truce with a rival family. When she refuses he more or less disowns her and to keep the peace Leo takes her to France and enrols her in the Sorbonne University. Here she meets Steve, a young American of Yugoslavian heritage, who has come to Paris to follow his dream of becoming  writer. They fall in love, but Alix is already in an abusive relationship with Raoul, a communist fellow student. The year is 1939 and when war breaks out she is trapped behind enemy lines . When Raoul is called up she feels she cannot break up with him while he is facing possible death in battle, so Steve goes to England and volunteers for the RAF.

Leo goes back to England to give Sasha time to simmer down.  She rejoins her old colleagues in the FANY and takes part in an expedition to Finland. The Finns are fighting a war with Russia and the FANY are asked to provide ambulances for their casualties. On her return she  meets Brigadier Colin Gubbins, the head of SOE, who asks her to go back to Yugoslavia to pass on information about the attitude of the regent, Prince Paul, who is being pressured to sign a pact with Hitler. Leo agrees and she and Sasha are reconciled and find themselves involved in a plot to depose Paul and replace him with the seventeen-year-old King Peter.

Alix, meanwhile, has joined the fledgling resistance and has taken on the hazardous job of accompanying downed airmen through occupied territory down to the south of France, so they can be returned to England to carry on the fight.  When the escape line is compromised and a number of leading members arrested she realises she must get away and heads back to Serbia.

The coup is successful but Hitler is so furious at having his plans thwarted that he declares all out war on Yugoslavia. On the day Alix arrives home he launches a massive bombing raid on Belgrade.

When I started researching this book and the sequels I knew very little about Yugoslavia at that period. I have found it an education! The complexity of the relationships between the various states that had been drawn together under that name – Serbia, Croatia, Montenegro, Macedonia, Slovenia – takes a long while to unravel. It became even more complex when I started work on the war itself and found myself following the rise of the man who became known to the world as President Tito.