will cut the
perpendicular. These will form the precise lines of your defense."

"The devil!" said D'Artagnan, stopping at this point of the
demonstration; "why, this is a complete system, Porthos."

"Entirely," said Porthos. "Continue."

"No; I have read enough of it; but, since it is you, my dear Porthos,
who direct the works, what need have you of setting down your system so
formally in writing?"

"Oh! my dear friend, death!"

"How! death?"

"Why, we are all mortal, are we not?"

"That is true," said D'Artagnan; "you have a reply for everything, my
friend." And he replaced the plan upon the stone.

But however short the time he had the plan in his hands, D'Artagnan had
been able to distinguish, under the enormous writing of Porthos, a
much more delicate hand, which reminded him of certain letters to
Marie Michon, with which he had been acquainted in his youth. Only the
India-rubber had passed and repassed so often over this writing that it
might have escaped a less practiced eye than that of our musketeer.

"Bravo! my friend, bravo!" said D'Artagnan.

"And now you know all that you want to know, do you not?" said Porthos,
wheeling about.

"Mordioux! yes, only do me one last favor, dear friend!"

"Speak, I am master here."

"Do me the pleasure to tell me the name of that gentleman who is walking
yonder."

"Where, there?"

"Behind the soldiers."

"Followed by a lackey?"

"Exactly."

"In company with a mean sort of a fellow, dressed in black?"

"Yes, I mean him."

"That is M. Getard."

"And who is Getard, my friend?"

"He is the architect of the house."

"Of what house?"

"Of M. Fouquet's house."

"Ah! ah!" cried D'Artagnan, "you are of the household of M. Fouquet,
then, Porthos?"

"I! what do you mean by that?" said the topographer, blushing to the top
of his ears.

"Why, you say the house, when speaking of Belle-Isle, as if you were
speaking of the chateau of Pierrefonds."

Porthos bit his lips. "Belle-Isle, my friend," said he, "belongs to M.
Fouquet, does it not?"

"Yes, I believe so."

"As Pierrefonds belongs to me?"

"I told you I believed so; there are no two words to that."

"Did you ever see a man there who is accustomed to walk about with a
ruler in his hand?"

"No; but I might have seen him there, if he really walked there."

"Well, that gentleman is M. Boulingrin."

"Who is M. Boulingrin?"

"Now, we are coming to it. If, when this gentleman is walking with