In the past I had cherry picked the books in the Alex Cross series to read and then recently I decided to start with the first one and work my way through the series. I am so glad that I did (even if it means re-reading some of the books). Not only are the main characters constant throughout the series, but many of the "bad" guys return with cameos or are referred to in later books. Don't get me wrong, you can definitely pick up any book in the series and have an enjoyable read, but it is much more meaningful if you start with the first one. Pop Goes the Weasel is no different. Throughout the book is references to the previous stories (going all the way back to Kiss the Girls) and after reading I have a feeling that the "bad" guy will make another appearance in a future book. The next two books in the series, Roses Are Red and Violets are Blue, I read a couple of years ago but can't wait to read them again after the enthralling Pop Goes the Weasel.