Sherlock Series 3: 20 Canonical References You May Have Missed

12. Jones

Most Holmes fans know who Lestrade is, and usually Gregson too, but there are also other police officers in the canon, such as Athelney Jones. In The Sign of Three, Lestrade is finally about to arrest the Waters family when Sherlock urgently requests his assistance, Donovan tells Lestrade that Jones will get all of the credit if he leaves now but Lestrade leaves anyway. That scene is a reference to the ending of The Sign of Four, Holmes solves the case but lets Jones have the credit, to which Watson responds, "You have done all the work in this business. I get a wife out of it, Jones gets the credit, pray what remains for you?"

11. John Or James?

The text message Mary receives in The Empty Hearse contains the phrase "John or James Watson", a reference to The Man With The Twisted Lip, in which Mary calls John "James". Mary calling him James is also what prompted many fans into speculating that John's middle name is Hamish, an Anglicisation of Sheumais, the vocative form of the Scottish Gaelic for James, Seumas. The skip code in the text message is also a reference to The Adventure of the Gloria Scott, where Holmes solves a similar code.

10. Drug Den

The opening of His Last Vow, which has John going to a drug den to pick up his neighbors son and then coincidentally finding Sherlock, almost exactly mirrors the beginning of The Man With the Twisted Lip.