Distilling the Essence of a Story

I have an interview on BlogTalkRadio on Saturday, September 5 at 11:30am ET. We're going to be talking about back story — where I got the ideas for A Spark of Heavenly Fire and More Deaths Than One. Although one of the hosts of the show has read at least one of my books, I'm sure at some point he will ask me, "What are your books about?" And I will give the same answer I give to everyone who asks. A blank stare. Though, being radio, it will come across as blank silence.

How does one encapsulate a