To this day, the expression "Jekyll and Hyde personality" characterizes a person at war with his darker side. After a century of psychological breakthroughs, why does this image still seem true? Basing their work on impressive research, authors McNally and Florescu shine a light into the mystery. They begin by recounting the life and times of William Deacon Brodie, the criminal who inspired the tale, and move on to Robert Louis Stevenson, the author who penned it. The authors track the many reincarnations of the story in popular culture (Dr. Jekyll and Mr. Hyde has become the subject of over one hundred motion-picture adaptations). The Strange Case of Dr. Jekyll and Mr. Hyde is more than just a ripping good yarn; as McNally and Florescu demonstrate, it is an insight into human nature and the true character of evil.