Classic crime novels often revolve around a variety of intriguing themes that make them captivating reads. The most prevalent theme is the investigation of a crime, usually a murder, with the story unfolding through the eyes of a detective. This detective, often an ordinary person or a charismatic character with unique abilities, uses logic and deduction to solve the mystery, which is a major theme in 'Classic Crime Novels Every Mystery Fan Should Read'. Other common themes include the exploration of human nature and societal issues, the battle between good and evil, and the pursuit of justice. These classic novels also frequently use settings that contribute to the eerie atmosphere, such as isolated country houses, dark alleyways, or gloomy mansions. These themes not only serve to engage the reader but also provide a deeper understanding of society and human psychology, making these classic crime novels timeless masterpieces in literature.