The Cthulhu Casebooks - Sherlock Holmes and the Miskatonic Monstrosities, Hardcover

His health nearly broken after a decade combating eldritch entities and evil cultists, Holmes must marshal his inner resources in order to tackle his most dangerous and terrifying case yet.
Miskatonic University in Arkham, Massachusetts, has a new resident academic, a certain Professor James Moriarty. In tandem with a young biology undergraduate called Herbert West, Moriarty is attempting a diabolical experiment that will enable him to conquer the world on behalf of his evil, elder-god masters.
Holmes and Watson must travel to America to stop their nemesis before he can tap the secrets of the fabled Necronomicon and unleash hell on earth.