Blue Moon continues the adventures of Anita Blake. In this novel, Anita travels to Myerton, Tennessee to help clear her ex-boyfriend Richard of rape allegations. In the process, Anita and her various allies are drawn into a supernatural conflict with the Master Vampire of that city, as well as the criminal scheme that Richard's frame-up was meant to conceal. As with the other later novels in the series, Blue Moon blends elements of supernatural, hardboiled detective, and erotic fiction.
As with previous novels, "Blue Moon" refers to a location within the novel itself. In this case, the "Blue Moon cabins" are a set of rental cabins owned by Verne, the local Ulfric. Within the novel, the term "blue moon" is also used to refer to an upcoming full moon, the second in that calendar month, which is a rare occurrence.