The Adventure of the Blue Carbuncle, one of the 56 short Sherlock Holmes stories written by Sir Arthur Conan Doyle, is the seventh story of twelve in The Adventures of Sherlock Holmes. The story was first published in Strand Magazine in January 1892.
As London prepares for Christmas, newspapers report the theft of the near priceless jewel, the 'Blue Carbuncle'. John Horner, a plumber and a previously convicted felon, is soon arrested for the theft. Though the police have yet to find the jewel, and despite Horner's claims of innocence, the police are sure that they have the thief.
Just after Christmas, Watson pays a visit to Holmes at 221B Baker Street. He finds the detective contemplating a battered old hat, one brought to him by the commissionaire Peterson. Both the hat and a Christmas goose had been dropped by a man in a scuffle with some street ruffians. Peterson, an honest man, had hoped for Holmes' help in returning the items to their owner; the goose bears a tag with the owner's name - Henry Baker:
“So much for Mr. Henry Baker,” said Holmes when he had closed the door behind him. “It is quite certain that he knows nothing whatever about the matter. Are you hungry, Watson?”
“Not particularly.”
“Then I suggest that we turn our dinner into a supper and follow up this clue while it is still hot.”
“By all means.”
It was a bitter night, so we drew on our ulsters and wrapped cravats about our throats. Outside, the stars were shining coldly in a cloudless sky, and the breath of the passers-by blew out into smoke like so many pistol shots. Our footfalls rang out crisply and loudly as we swung through the doctors’ quarter, Wimpole Street, Harley Street, and so through Wigmore Street into Oxford Street. In a quarter of an hour we were in Bloomsbury at the Alpha Inn, which is a small public-house at the corner of one of the streets which runs down into Holborn.