The Hanging Girl is book six in the Department Q series. Department Q is the Danish cold-case division that is headed up by Carl Morck. Perhaps it could be read as a stand-alone, personally, I would recommend reading the series in order so that you can fully appreciate the evolution of the characters.
It has been three years since Carl, Assad and Rose investigated The Marco Effect. That’s a large chunk of time that I missed in the lives of Department Q. Over that period the team has grown closer, becoming an efficient unit. There have been many changes in Carl’s personal life as well. It really says something about the characters that Adler-Olsen has created. I felt cheated in the fact that I missed all of this time, these important transitions in their lives. I’ve been with these characters for six books now, they are so real that I feel as if I know them.
Adler-Olsen has crafted another unique case, making some significant changes to the formula. In the past, we knew the villain, often getting the perpetrator’s point of view. The previous books have been more of a cat-and-mouse, rather than the who-done-it that The Hanging Girl is. There are several suspects, all of whom had motive. I enjoyed the change of pace. I think it’s important for an author to change things up in a series so that it doesn’t become too repetitive and formulaic.
The only issue that I had with The Hanging Girl was that there was a noticeable reduction in the comic relief. It’s only natural that the team has grown closer together, the peculiarities that were once annoying have become accepted as “normal” after all these years.