The Hounds of Baskerville order to test his theory. He also points out Sherlock was wrong for once; he believed the drug was in Henry's sugar and put it in John's coffee. In the closing scenes, Mycroft oversees the release of Jim Moriarty (Andrew Scott) from a holding cell in which he has written Sherlock's name all over the walls. The story is based on Arthur Conan Doyle's novel "The Hound of the Baskervilles", and also contains plot devices and lines from other Doyle stories: In June 2011, it was announced that Russell Tovey would appear in "Sherlock" series two in its second episode.
The Hound of the Baskervilles to move into Baskerville Hall, despite the ominous warning message. Holmes and Dr Watson follow him from Holmes's Baker Street apartment back to his hotel and notice a bearded man following him in a cab; they pursue the man, but he escapes. Mortimer tells them that Mr Barrymore, the butler at Baskerville Hall, has a beard like the one on the stranger. Sir Henry's boot reappears, but an older one vanishes. Holmes sends for the cab driver who shuttled the bearded man after Sir Henry and is both astounded and amused to learn that the stranger had made a point