Though it may be a well-written prize winner, a one-off book, a stand-alone novel, has little chance of commercial success in today's reading market. The mass of readers wants recurring heroes, protagonists who return to deliver the goods in more adventures. It's something a reader can look forward to and feel comfortable with. Series novels are the thing. And looking back, reading of the army of fans who followed Arthur Conan-Doyle and eagerly awaited his latest Sherlock Holmes treat, I feel it's always been so. Now it's big time. Series novels are invariably thrillers in the crime, mystery and espionage genres. Some come about by accident. They begin with a single book, which is then followed by another , perhaps a sequel, and then a third and so it goes on. Others are intended from the beginning. My new novel, 'The Sum of Things' recently launched on Amazon's Kindle, is one of these. It's the first in what I intend and to be a long and successful se