"When Dr John Watson takes rooms in Baker Street with amateur detective Sherlock Holmes, he has no idea that he is about to enter a shadowy world of criminality and violence. Accompanying Holmes to an ill-omened house in south London, Watson is startled to find a dead man whose face is contorted in a rictus of horror. There is no mark of violence on the body yet a single word is written on the wall in blood. Dr Watson is as baffled as the police,...

"I am inclined to think—" said I. "I should do so," Sherlock Holmes remarked impatiently. I believe that I am one of the most long-suffering of mortals; but I'll admit that I was annoyed at the sardonic interruption. "Really, Holmes," said I severely, "you are a little trying at times." He was too much absorbed with his own thoughts to give any immediate answer to my remonstrance. He leaned upon his hand, with his untasted breakfast before...