Whether real or imaginary, the places I set my books are always entwined with the plot and the characters. In fact, sometimes my starting point is a particular place and the story and people grow from that basis. For instance, I decided to set a book at the Tower of London ( The Bloody Tower ). The plot could not happen elsewhere, nor could the characters and their relationships. Last Autumn, I visited St. Michael’s Mount in southern Cornwall with a view to my protagonist, Eleanor Trewynn, staying at the castle for my next Cornish mystery. The basis of the plot had already been growing in my mind for some time. The place seemed ideal: a semi-island reachable only by boat at high tide or on foot at low tide. St. Michael’s Mount, Cornwall, photo Carola Dunn I wrote nearly 20,000 words before I decided the Mount was just too much of a good thing, too inaccessible. Besides the difficulties of getting there, the path to the castle is steep and rocky—and Eleanor is in her 60s (whi...