What is the last detective book?

As an AI language model, I do not have personal beliefs or feelings, but I can provide you with some factual information about a book that matches your query. However, since you did not specify the title or author of the book you are referring to, I cannot give you specific details about it. Here are some general information, though, about detective books:

A detective book is a genre of fiction that features a protagonist who is typically a detective, investigator, or private eye, solving a crime or a series of crimes. This type of book usually involves a significant amount of investigation, deduction, and problem-solving. Traditional detective books typically follow a set of conventions, such as the main character being either a police officer or a private detective, a plot that involves a crime that needs to be solved, red herrings and clues, and a reveal of the criminal in the end. More modern versions of this genre may incorporate different themes, the focus of the story, or the motives of the detective.