Mary Shelley's creation, Frankenstein, who emerged from a dream by a young woman who had just lost her first child, has transformed itself into a warning about the dangers of tampering with nature. The vampire started life as a sexual fantasy, and Bram Stoker's tale became a metaphor for dominance and dependence in sexual relationships. Dr Jekyll and Mr Hyde, perhaps the most psychological of all horror stories, examines the beast in man and the dark side of human nature. And The Hound of the Baskervilles is a tale of conflict between rationalism and folklore, and the skills of Sherlock Holmes.