where the path met the horizon.
When Beautrelet, in his turn, emerged from the wood, he was greatly surprised no longer to see the man. He was seeking him with his eyes when, suddenly, he gave a stifled cry and, with a backward spring, made for the line of trees which he had just left. On his right, he had seen a rampart of high walls, flanked, at regular distances, by massive buttresses.
It was there! It was there! Those walls held his father captive! He had found the secret place where Lupin confined his victim.
He dared not quit the shelter which the thick foliage of the wood afforded him. Slowly, almost on all fours, he bore to the right and in this way reached the top of a hillock that rose to the level of the neighboring trees. The walls were taller still. Nevertheless, he perceived the roof of the castle which they surrounded, an old Louis XIII. roof, surmounted by very slender bell-turrets arranged corbel- wise around a higher steeple which ran to a point.
Beautrelet did no more that day. He felt the need to reflect and to prepare his plan of attack without leaving anything to chance. He held Lupin safe; and it was for Beautrelet now to select the hour and the manner of the combat.
He walked away.
Near the bridge, he met two country-girls carrying pails of milk. He asked:
"What is the name of the castle over there, behind the trees?"
"That's the Chateau de l'Aiguille, sir."
He had put his question without attaching any importance to it. The answer took away his breath:
"The Chateau de l'Aiguille?—Oh!—But in what department are we? The Indre?"
"Certainly not. The Indre is on the other side of the river. This side, it's the Creuse."
Isidore saw it all in a flash. The Chateau de l'Aiguille! The department of the Creuse! L'AIGUILLE CREUSE! The Hollow Needle! The very key to the document! Certain, decisive, absolute victory!
Without another word, he turned his back on the two girls and went his way, tottering like a drunken man.
Chapter 6 An Historic Secret
Beautrelet's resolve was soon taken: he would act alone. To inform the police was too dangerous. Apart from the fact that he could only offer presumptions, he dreaded the slowness of the police, their inevitable indiscretions, the whole preliminary inquiry, during which Lupin, who was sure to be warned, would have time to effect a retreat in good order.
At eight o'clock the next morning, with his bundle under his arm, he left the inn in which he was staying near Cuzion, made for the nearest thicket, took off his workman's clothes, became once more the young English painter that he had been and went to call on the notary at Eguzon, the largest place in the immediate neighborhood.
He said that he liked the country and that he was thinking of taking up his residence there, with his relations, if he could find a suitable house.
The notary mentioned a number of properties. Beautrelet took note of them and let fall that some one had spoken to him of the Chateau de l'Aiguille, on the bank of the Creuse.
"Oh, yes, but the Chateau de l'Aiguille, which has belonged to one of my clients for the last five years, is not for sale."
"He lives in it, then?"
"He used to live in it, or rather his mother did. But she did not care for it; found the castle rather gloomy. So they left it last year."
"And is no one living there at present?"
"Yes, an Italian, to whom my client let it for the summer season: Baron Anfredi."
"Oh, Baron Anfredi! A man still young, rather grave and solemn- looking—?"
"I'm sure I can't say.—My client dealt with him direct. There was no regular agreement, just a letter—"
"But you know the baron?"
"No, he never leaves the castle.—Sometimes, in his motor, at night, so they say. The marketing is done by an old cook, who talks to nobody. They are queer people—"
"Do you think your client would consent to sell his castle?"
"I don't think so. It's an historic castle, built in the purest Louis XIII. style. My client was very fond of it; and, unless he has changed his mind—"
"Can you give me his name and address?"
"Louis Valmeras, 34, Rue du Mont-Thabor."
Beautrelet took the train for Paris at the nearest station. On the next day but one, after three fruitless calls, he at last found Louis Valmeras at home. He was a man of about thirty, with a frank and pleasing face. Beautrelet saw no need to beat about the bush, stated who he was and described his efforts and the object of the step which he was now taking:
"I have good reason to believe," he concluded, "that my father is imprisoned in the Chateau de l'Aiguille, doubtless in the company of other victims. And I have come to ask you what you know of your tenant, Baron Anfredi."
"Not much. I met Baron Anfredi last winter at Monte Carlo. He had heard by accident that I was the owner of the Chateau de l'Aiguille and, as he wished to spend the summer in France, he made me an offer for it."
"He is still a young man—"
"Yes, with very expressive eyes, fair hair—"
"And a beard?"
"Yes, ending in two points, which fall over a collar fastened at the back, like a clergyman's. In fact, he looks a little like an English parson."
"It's he," murmured Beautrelet, "it's he, as I have seen him: it's his exact description."
"What! Do you think—?"
"I think, I am sure that your tenant is none other than Arsene Lupin."
The story amused Louis Valmeras. He knew all the adventures of Arsene Lupin and the varying fortunes of his struggle with Beautrelet. He rubbed his hands:
"Ha, the Chateau de l'Aiguille will become famous!—I'm sure I don't mind, for, as a matter of fact, now that my mother no longer lives in it, I have always thought that I would get rid of it at the first opportunity. After this, I shall soon find a purchaser. Only—"
"Only what?"
"I will ask you to act with the most extreme prudence and not to inform the police until you are quite sure. Can you picture the situation, supposing my tenant were not Arsene Lupin?"
Beautrelet set forth his plan. He would go alone at night; he would climb the walls; he would sleep in the park—
Louis Valmeras stopped him at once:
"You will not climb walls of that height so easily. If you do, you will be received by two huge sheep-dogs which belonged to my mother and which I left behind at the castle."
"Pooh! A dose of poison—"
"Much obliged. But suppose you
