Murder at the Merton Library is a serviceable mystery. The allure of the book is the history of the characters and their relationships that developed over the previous installments. This mystery was not too difficult to suss out. The perpetrators were not as well drawn as previous villains. However, I found the historical information to be interesting and I do enjoy many of the secondary characters. I hope the future books in the series pick up pace and characterization better. It was a diverting read but not anything spectacular.