THE SPIES OF SHILLING LANE began life a few years ago, when I interviewed a twinkly-eyed old lady, Mrs. Underwood, about life in Britain during the Second World War.

"I hate to confess it, but it was the best time of my life," she said with a mischievous half-smile. "The freedom we girls had! I went to London and took a job that in any other time would have been done by a man. But they were needed for fighting, you see."

I asked her what work she did.

Her eyes gleamed. "I worked for one of the big spy agencies, MI5. I can't tell you what I did, as I had to sign the Official Secrets Act."

No matter how much I assured her that seventy years after the end of the war, it was unlikely that anyone would imprison a ninety-year-old woman for sharing her wartime experiences.

But she only did that coquettish zipping her lips motion, again with that amused half-smile.

Had she been a spy?

"My mother hated me working," she said, trying to change the subject. "I came from a well-to-do family, and she thought I should stay at home and get married in case there weren't enough men to go around after the war--that happened in the First World War, you see."

"But you stayed in London, working." I tried to get back to her work.

She grinned. "We girls had a lot of freedom. There were a lot of dances, parties, bombs, nights in the shelters. Life was a chaotic mixture of fear and hedonism."

Suddenly, behind her lively pale blue eyes, I saw her as a young woman, vibrant, ready for anything, willing to give her all to save the country from the Nazis. And as she gave me her half-smile, I began to imagine what kind of spy she had been.

She became Betty Braithwaite, and of course, her mother became the one and only Mrs. Braithwaite.

And today, after years of research, writing, editing, printing, and general worrying, the book is in stores around the country. I hope you enjoy reading it as much as I loved researching and writing about these brave and fearless women.