"Such a plague has descended upon Dijon," Hanaud continued. "For more than a year it has raged. The police would not apply to Paris for help. No, they did not need help, they would solve this pretty problem for themselves. Yes, but the letters go on and the citizens complain. The police say, 'Hush! The examining magistrate, he has a clue. Give him time!' But the letters still go on. Then after a year comes this godsend of the Waberski affair. At once the Prefect of Police and the magistrate put their heads together. 'We will send for Hanaud over this simple affair, and he will find for us the author of the anonymous letters. We will send for him very privately, and if any one recognises him in the street and cries "There is Hanaud," we can say he is investigating the Waberski affair. Thus the writer of the letters will not be alarmed and we—we excuse our faces.' Yes," concluded Hanaud heatedly, "but they should have sent for me a year ago. They have lost a year."
"And during that year the dreadful things have happened?" asked Jim.
Hanaud nodded angrily.
"An old, lonely man who lunches at the hotel and takes his coffee at the Grande Taverne and does no harm to any one, he flings himself in front of the Mediterranean express and is cut to pieces. A pair of lovers shoot themselves in the Forêt des Moissonières. A young girl comes home from a ball; she says good night to her friends gaily on the doorstep of her house, and in the morning she is found hanging in her ball dress from a rivet in the wall of her bedroom, whilst in the hearth there are the burnt fragments of one of these letters. How many had she received, that poor girl, before this last one drove her to this madness? Ah, the magistrate. Did I not tell you? He has need to excuse his face."
Hanaud opened a drawer in his desk and took from it a green cover.
"See, here are two of those precious letters," and removing two typewritten sheets from the cover he handed them to Frobisher. "Yes," he added, as he saw the disgust on the reader's face, "those do not make a nice sauce for your breakfast, do they?"
"They are abominable," said Jim. "I wouldn't have believed——" he broke off with a little cry. "One moment, Monsieur Hanaud!" He bent his head again over the sheets of paper, comparing them, scrutinising each sentence. No, there were only the two errors which he had noticed at once. But what errors they were! To any one, at all events, with eyes to see and some luck in the matter of experience. Why, they limited the area of search at once!
"Monsieur Hanaud, I can give you some more help," he cried enthusiastically. He did not notice the broad grin of delight which suddenly transfigured the detective's face. "Help which may lead you very quickly to the writer of these letters."
"You can?" Hanaud exclaimed. "Give it to me, my young friend. Do not keep me shaking in excitement. And do not—oh! do not tell me that you have discovered that the letters were typed upon a Corona machine. For that we know already."
Jim Frobisher flushed scarlet. That is just what he had noticed with so much pride in his perspicuity. Where the text of a sentence required a capital D, there were instead the two noughts with the diagonal line separating them (thus, %), which are the symbol of "per cent."; and where there should have been a capital S lower down the page, there was the capital S with the transverse lines which stands for dollars. Jim was familiar with the Corona machine himself, and he had remembered that if one used by error the stop for figures, instead of the stop for capital letters, those two mistakes would result. He realised now, with Hanaud's delighted face in front of him—Hanaud was the urchin now—that the Sûrété was certain not to have overlooked those two indications even if the magistrate at Dijon had; and in a moment he began to laugh too.