Welcome!

You're about to embark on one of Sherlock Holmes' adventures.
Here, you will read Dr. John Watson's account of the curious matter of the Blue Carbuncle.
However, you will do more than just reading. In fact, as you move on with the story, you will help England's most famous detective solve this case. Read on to know how.

'The game's afoot!' You can already hear Sherlock Holmes' shout of delight as this new case starts.
Press the button whenever you're ready to shout it with him.

"This hat you see here came to me with a strange companion, a goose. On Christmas morning, they were left on the street by a man running away from a brawl. Then, they were found and brought to me by Mr. Peterson, my neighbour who works as a commissionaire at the Hotel Cosmopolitan.
Before I tell you about that, however, let us see if your deduction skills have weakened since you married and moved out!

Below, you can see ten observations we can rather easily make as we study this hat.
Of course, for each observation we can also make a deduction.
It is now your job, dear Watson, to see if you can choose the right one. After you have accomplished this task, I will tell you more of the hat and goose."

"Not as sharp as in the past, uh, Watson? Let us go in order: a big hat covers a big head, which must have something in it! Then, this type of hat is of excellent quality and came out three years ago. So, the man must have been rich then, but poorer know seeing as he hasn't bought a new hat all this time. The amount of dust on it tells us two things: the man doesn't go out often and his wife doesn't care about letting him go out with such a dirty hat, so she must have ceased to love him. The ink tells us that the man doesn't want to show his worsened condition, and what can be found on the inside, sweat and hair, makes us deduce he's in poor shape and had his hair cut recently. Finally, the scent of citrus is revealing of the lime-cream anointment, much as the tallow stains are of his use of candles in the house, where there's no gas. Now..."

As Holmes was speaking, the door flew open and Peterson rushed into the apartment with flushed cheeks and an astonished face. "The goose, sir! The goose! Look what my wife has found in its crop!", the man gasped as he showed us a brilliantly scintillating blue stone, rather smaller than a bean in size, but of such purity and radiance that it twinkled like an electric point in the dark hollow of his hand. "By Jove, Watson!" exclaimed Holmes. "That is the Countess of Morcar's blue carbuncle! It is absolutely unique and its value can only be conjectured. It was lost on December 22nd at the Hotel Cosmopolitan. John Horner, a plumber, was accused by James Ryder, upper-attendant at the hotel, of stealing it after having done some maintenance work in the room. Mr. Ryder had left Mr. Horner in the room where he later found the Countess' jewel casket open and empty. Catherine Cusack, maid to the Countess, corroborated Ryder's testimony. Now, the question is: how did a diamond stolen from the Hotel Cosmopolitan end in that bird's crop?"

That evening, it was a little after half past six when we heard a knock on the door and welcomed Henry Baker in our apartment. He was a large man with rounded shoulders, a massive head, and a broad, intelligent face, sloping down to a pointed beard of grizzled brown.
"Mr. Baker, we have retained these things for some days," said Holmes, "because we expected to see an advertisement from you giving your address."
"Shillings have not been so plentiful with me as they once were," he remarked. "I had no doubt that the gang of roughs who assaulted me had carried off both my hat and the bird. I did not care to spend more money in a hopeless attempt at recovering them."

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.
Before pushing open the door of the bar, Holmes asked me: "What do you think, Watson? Should we reveal our business to the owner or pretend we're here for a drink and are just curious about that goose?"

Holmes and I walked out of the pub and marched quickly to the Covent Garden Market. As we were approaching Breckinridge's stall, we saw a strange scene take place. A man, whom we understood to be Breckinridge himself, was pinning another man to the wall, shouting: "Enough of these geese! It's no business of yours whom I sold the lot to!" "It is only one I am interested in...", whined the little man. "Kind sir, leave the matter to me," intervened Holmes. "I'm with the police."

After managing to set the the second man free, we asked him his name. "John Robinson", he answered with a sidelong glance. "No, no; the real name," said Holmes sweetly. "It is always awkward doing business with an alias." "Well, then," said he, "my real name is James Ryder." "Precisely so. Head attendant at the Hotel Cosmopolitan. Now for my apartment, Ryder. There you shall tell us all of this business."