[1][2][3] The House of Silk begins with a brief, personal recounting of events by Watson, much like that in A Study in Scarlet by the original author, Sir Arthur Conan Doyle.

The reader is informed of the particulars regarding the first meeting of Watson and Holmes, including the circumstances of the Afghan War and a mention of the case that was "too shocking to be revealed until now."

The client of "The Flat Cap case" is introduced as a man by the name of Edmund Carstairs, an art dealer whose paintings had been destroyed by a gang of Irish robbers.

After the murder of Carstairs' client, and a failure on the part of a hired detective, he turns to Sherlock Holmes, who employs the aid of the Baker Street Irregulars, and upon locating the hotel wherein the supposed Keelan O'Donaghue (one of the leaders of the gang) is currently staying, one of the newest recruits of the Irregulars, a boy named Ross, is stationed to wait outside until Holmes, Watson, and Mr. Carstairs arrive.

Professor Moriarty's motives are uncertain, except that he wishes Holmes to rid the world of the House of Silk, whose activities apparently appall even him.