“In Kennington Road, and within a few hundred yards of Morse Hudson’s shop, there lives a well-known medical practitioner, named Dr. Barnicot, who has one of the largest practices upon the south side of the Thames. His residence and principal consulting-room is at Kennington Road, but he has a branch surgery and dispensary at Lower Brixton Road, two miles away. This Dr. Barnicot is an enthusiastic admirer of Napoleon, and his house is full of books, pictures, and relics of the French Emperor. Some little time ago he purchased from Morse Hudson two duplicate plaster casts of the famous head of Napoleon by the French sculptor, Devine. One of these he placed in his hall in the house at Kennington Road, and the other on the mantelpiece of the surgery at Lower Brixton. Well, when Dr. Barnicot came down this morning he was astonished to find that his house had been burgled during the night, but that nothing had been taken save the plaster head from the hall. It had been carried out and had been dashed savagely against the garden wall, under which its splintered fragments were discovered.”

Holmes rubbed his hands.

“This is certainly very novel,” said he.

“I thought it would please you. But I have not got to the end yet. Dr. Barnicot was due at his surgery at twelve o’clock, and you can imagine his amazement when, on arriving there, he found that the window had been opened in the night, and that the broken pieces of his second bust were strewn all over the room. It had been smashed to atoms where it stood. In neither case were there any signs which could give us a clue as to the criminal or lunatic who had done the mischief. Now, Mr. Holmes, you have got the facts.”

“They are singular, not to say grotesque,” said Holmes. “May I ask whether the two busts smashed in Dr. Barnicot’s rooms were the exact duplicates of the one which was destroyed in Morse Hudson’s shop?”

“They were taken from the same mould.”

“Such a fact must tell against the theory that the man who breaks them is influenced by any general hatred of Napoleon. Considering how many hundreds of statues of the great Emperor must exist in London, it is too much to suppose such a coincidence as that a promiscuous iconoclast should chance to begin upon three specimens of the same bust.”

“Well, I thought as you do,” said Lestrade. “On the other hand, this Morse Hudson is the purveyor of busts in that part of London, and these three were the only ones which had been in his shop for years. So, although, as you say, there are many hundreds of statues in London, it is very probable that these three were the only ones in that district. Therefore, a local fanatic would begin with them. What do you think, Dr. Watson?”

“There are no limits to the possibilities of monomania,” I answered. “There is the condition which the modern French psychologists have called the ‘idée fixe,’ which may be trifling in character, and accompanied by complete sanity in every other way. A man who had read deeply about Napoleon, or who had possibly received some hereditary family injury through the great war, might conceivably form such an idee fixe and under its influence be capable of any fantastic outrage.”

“That won’t do, my dear Watson,” said Holmes, shaking his head, “for no amount of idée fixe would enable your interesting monomaniac to find out where these busts were situated.”

“Well, how do you explain it?”