For most of my writing career, I have always enjoyed the mystery novel. The challenge of writing a puzzle always got me excited about the craft of putting together a book. With a mystery, the reader does not know the killer. At least not right away. Now, enter the thriller. Here, the killer very well might be introduced to the reader and it's up to the protagonist to figure things out. I moved from the ranks of mystery writer to thriller writer because I wanted to put even more action in my books. Enter Frank Tower. A former police officer, now private investigator. In his first appearance as lead protagonist, I wrote the book Pearls. A lot of action and I am contemplating writing the screenplay. In the next book, one that I am writing now, called Down to the Last Mark, again, there is action from page one. It's a different challenge. And one that I enjoy. There is also a lot of suspense. Either mystery or thriller, enjoy. Just remember, for the author, it is also a joy just to sit down and write it.