Trying to justify a world we don't hold all the answers to is what bedevils the best of us. Sometimes it's better just to accept that things are as we see them.

With The Nightingale, I had been kicking the idea around for years. I was frightened to write it because on the surface it seems so different for me.

The women of the French Resistance astounded me. Isabelle and Vianne [from The Nightingale] are my homage to those brave and forgotten women.

Andrée De Jongh story led me to other stories of women who joined the Resistance in France. I found literally dozens of memoirs written by women who had become spies and couriers and helped to create the escape network. These women were like action-star heroes.

In the end, the best part of the whole book [The Nightingale ] to me was the research, reading about the courageous, ordinary French women who put their lives on the line to save others. It was really inspirational.

Calling it lunacy makes it easier to explain away the things we don't understand.

I love women being the heroes of the piece. There is just something so dramatic and important about this story [The Nightingale ].