"If you ever wondered how much better Sherlock would be if people could hurl hellfire at each other, well this one is for you." Starburst Magazine on A Study in Brimstone
Warlock Holmes may have demons in his head, but now Dr. John Watson has a mummy in his bloodstream. Specifically that of the sorcerer Xantharaxes, who when shredded and dissolved in an 8% solution, results in some extremely odd but useful prophetic dreams.
There's also the small matter of Watson falling for yet another damsel-du-jour, and Warlock deciding that his companion needs some domestic bliss...