In the stews of London’s East End, an outbreak of insanity sees ordinary men and women reduced to gibbering, incoherent wrecks; a mysterious creeping fog hides terrifying apparitions within that rob the wits of all who see them and even inspire suicide. Sherlock Holmes, in the infancy of his detecting career, deduces a connection between these sinister “shadows” and an Oriental drug lord who is bent on expanding his criminal empire. Yet there are even more sinister forces at work, as the great detective faces a challenge so fearsome and deadly that his career may be over almost as soon as it has begun.

It is the spring of 1895, and more than a decade of combating eldritch entities has cost Dr John Watson his beloved wife Mary, and nearly broken the health of Sherlock Holmes. Yet the companions do not hesitate when they are called to the infamous Bedlam lunatic asylum, where they find an inmate speaking in R’lyehian, the language of the Old Ones. Moreover, the man is horribly scarred and has no memory of who he is. The detectives discover that the inmate was once a scientist, a student of Miskatonic University, and one of two survivors of a doomed voyage down the Miskatonic River to capture the semi-mythical shoggoth. Yet how has he ended up in London, without his wits? And when the man is taken from Bedlam by forces beyond normal mortal comprehension, it becomes clear that there is far more to the case than one disturbed Bostonian. It is only by learning what truly happened on that fateful New England voyage that Holmes and Watson will uncover the truth, and learn who is behind the Miskatonic monstrosity…

The stunning new novel from the New York Times bestselling author of The Age of Odin, in which the worlds of Arthur Conan Doyle and H.P. Lovecraft collide. It is the autumn of 1910, and for fifteen long years Sherlock Holmes and Dr John Watson have battled R'lluhloig, the Hidden Mind that was once Professor James Moriarty. Europe is creeping inexorably towards war, and a more cosmic conflict is nearing its zenith, as in a single night all the most eminent members of the Diogenes Club die horribly, seemingly by their own hands. Holmes suspects it is the handiwork of a German spy working for R'lluhloig, but his search for vengeance costs an old friend his life. The companions retreat to Holmes' farm on the Sussex Downs, and it is not long before a client comes calling. Three young women have disappeared from the nearby town of Newford, and the locals have no doubt who is responsible. For legend has it that strange amphibious creatures dwell in a city on the seabed, coming ashore every few centuries to take fresh captives. As Holmes and Watson seek out the terrifying interlopers, the scene is set for the final battle that will bring them face to face with the Sussex Sea-Devils, and perhaps with Cthulhu himself...

An exciting standalone Cthulhu Casebooks narrative, a thrilling tale of mystery and dread, from the New York Times bestselling author. It’s 1929 and an ageing Dr John Watson, conscious of his imminent demise, finally sits down to write a fresh chronicle disclosing the true events behind his published accounts of Sherlock Holmes’s exploits. In these pages, Sherlock Holmes and his stalwart companion encounter reanimated corpses in Highgate Cemetery; a very different, though ever elusive, Irene Adler; tales of madness and murder in the frozen wastes of the north; grotesque organic machines; and much more. Each case brings the illustrious pair ever closer to the dramatic and terrifying truth about the mysterious aliens, the Mi-Go, and their plans for Earth…