Extremely well-researched -- she didn't just read about the once-popular puppet shows featuring murderers, she actually tried out the puppets! -- but wears its erudition lightly. Makes an original argument that true crime and crime fiction influenced each other as twinned types of popular entertainment in 19th and early 20th century England. She unapologetically holds Dorothy Sayers up as the epitome of British crime fiction -- without making any attempt to sugarcoat the author's many flaws as a human being -- and I think that gives you quite an accurate idea of Worsley's bluestocking Oxbridge charms.