In the fog-soaked streets of Victorian London, a respectable lawyer stumbles onto something deeply wrong. His old friend, the brilliant and well-loved Dr. Henry Jekyll, has tied himself – legally, irrevocably – to a man no one seems to know. A man called Hyde. A man who leaves witnesses shaken and unable to explain quite why the sight of him turns the stomach. What hold could this stranger possibly have over a gentleman of Jekyll's standing? Blackmail? An old debt? Something worse? As the lawyer pulls at the thread, the answer begins to unravel – and what waits at the end of it is stranger, and far more terrible, than any crime he's prepared to imagine. A slim, restless masterpiece that gave the world a phrase it has never stopped using, Stevenson's 1886 thriller still does what the best horror does: it whispers that the monster might not be out there at all.