From the supernatural case files of Sherlock Holmes:
Many of Holmes' more fantastic cases have yet to see publication, since their grotesque and outré nature would have stretched the listener's sensibilities beyond any normal boundaries. They are, in a word, unbelievable, and I have held these cases in abeyance at Holmes' request to protect both his reputation and my own small credibility as narrator.
But the time has come to reveal them, per Holmes' instructions. I follow these instructions faithfully and humbly, and let my readers judge if we have done wrong to withhold them for as long as we did.
- John H. Watson, M.D.
When a rare and lustrous pearl is discovered in Highgate Cemetery, it's the beginning of one of the most sinister cases Holmes and Watson have ever faced. And one with profoundly personal ramifications for the good doctor.