"See that your sons keep a good watch... If any one attempts to deliver him, so much the worse for him. The trapdoor is there. Can I rely upon them?"

"As thoroughly as on myself, monsieur le marquis," declared the huntsman. "They know what monsieur le marquis has done for me and what he means to do for them. They will shrink at nothing."

"Let us mount and get back to the hounds," said d'Albufex.

So things were going as Lupin had supposed. During these runs, d'Albufex, taking a line of his own, would push off to Mortepierre, without anybody's suspecting his trick. Sebastiani, who was devoted to him body and soul, for reasons connected with the past into which it was not worth while to inquire, accompanied him; and together they went to see the captive, who was closely watched by the huntsman's wife and his three sons.

"That's where we stand," said Lupin to Clarisse Mergy, when he joined her at a neighbouring inn. "This evening the marquis will put Daubrecq to the question - a littie brutally, but indispensably - as I intended to do myself."

"And Daubrecq wrn give up his secret," said Clarisse, already quite upset.

"I'm afraid so."

"Then... "

"I am hesitating between two plans," said Lupin, who seemed very calm. "Either to prevent the interview... "

"How?"

"By forestalling d'Albufex. At nine o'clock, the Growler, the Masher and I climb the ramparts, burst into the fortress, attack the keep, disarm the garrison... and the thing's done: Daubrecq is ours."

"Unless Sebastiani's sons fling him through the trapdoor to which the marquis alluded... "

"For that reason," said Lupin, "I intend to risk that violent measure only as a last resort and in case my other plan should not be practicable."

"What is the other plan?"

"To witness the interview. If Daubrecq does not speak, it will give us the time to prepare to carry him off under more favourable conditions. If he speaks, if they compel him to reveal the place where the list of the Twenty-seven is hidden, I shall know the truth at the same time as d'Albufex, and I swear to God that I shall turn it to account before he does."

"Yes, yes," said Clarisse. "But how do you propose to be present?"

"I don't know yet," Lupin confessed. "It depends on certain particulars which the Masher is to bring me and on some which I shall find out for myself."

He left the inn and did not return until an hour later as night was falling. The Masher joined him.

"Have you the little book?" asked Lupin.

"Yes, governor It was what I saw at the Aumale newspaper-shop. I got it for ten sous."

"Give it me."

The Masher handed him an old, soiled, torn pamphlet, entitled, on the cover, A Visit to Mortepierre, 1824, with plans and illustrations.

Lupin at once looked for the plan of the donjon-keep.

"That's it," he said. "Above the ground were three stories, which have been razed, and below the ground, dug out of the rock, two stories, one of which was blocked up by the rubbish, while the other... There, that's where our friend Daubrecq lies. The name is significant: the torture-chamber ... Poor, dear friend!... Between the staircase and the torture-chamber, two doors. Between those two doors, a recess in which the three brothers obviously sit, gun in hand."