"Well, I thought the same," said Lestrade. "On the other hand, this Morse Hudson is the main supplier of these busts in that part of London. These three busts 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 fanatic who lives nearby would begin by attacking them. What do you think, Dr. Watson?"

"There are no limits to what someone with monomania, might do" I answered. "There is the condition which modern French psychologists have called the "idee fixe". This may be something totally unimportant, and accompanied by complete sanity in every other way. For example, a man who had read a lot about Napoleon, or who had possibly had a member of his family injured in the Napoleonic wars, might perhaps get such an idee fixe. Under the influence of this he might be capable of any kind of strange or dangerous behaviour."

"That won't do, my dear Watson," said Holmes, shaking his head, "for no amount of idee fixe would enable your interesting monomaniac to find these busts in the first place."

"Well, how do you explain it?"