Strange Case of Dr Jekyll and Mr Hyde is a novella by the Scottish author Robert Louis Stevenson, first published in 1886. London lawyer Utterson is driven to investigate Edward Hyde, the unlikely protégé of his friend Dr Henry Jekyll, suspecting the relationship to be founded on blackmail. The truth is worse than he could have imagined. Jekyll's 'full statement of the case', the final chapter of the book, explores the idea of dual personality that led him to his experiments, and his inexorable and finally fatal descent into evil.