The year's best crime fiction offers more than just whodunits, delving into themes of power, moral compromise, and the consequences of violence. Books like Richard Osman's 'The Impossible Fortune' explore aging, loyalty, and regret with tenderness, while Peter Swanson's 'Kill Your Darlings' examines intimate betrayals and institutional rot. These thrillers dissect truth, deception, rage, and retribution, highlighting how past actions shape present dangers and societal ruptures.