he saw that
she was followed. She isn't able to get to see them outside, therefore
she has to see them inside."

"They are only one, and always the same one."

"Are you sure?"

"An examination of the marks on the wall and on the pipe doesn't leave
any doubt of it, and it is always the same grappling-iron that is used
for the window."

"The viper!"

"Monsieur Koupriane, Mademoiselle Natacha seems to preoccupy you
exceedingly. I did not come here to talk about Mademoiselle Natacha. I
came to point out to you the route used by the man who comes to do the
murder."

"Eh, yes, it is she who opens the way."

"I can't deny that."

"The little demon! Why does she take him into her room at night? Do you
think perhaps there is some love-affair...?"

"I am sure of quite the opposite."

"I too. Natacha is not a wanton. Natacha has no heart. She has only a
brain. And it doesn't take long for a brain touched by Nihilism to get
so it won't hesitate at anything."

Koupriane reflected a minute, while Rouletabille watched him in silence.

"Have we solely to do with Nihilism?" resumed Koupriane. "Everything you
tell me inclines me more and more to my idea: a family affair, purely in
the family. You know, don't you, that upon the general's death Natacha
will be immensely rich?"

"Yes, I know it," replied Rouletabille, in a voice that sounded singular
to the ear of the Chief of Police and which made him raise his head.

"What do you know?"

"I? Nothing," replied the reporter, this time in a firmer tone. "I
ought, however, to say this to you: I am sure that we are dealing with
Nihilism..."

"What makes you believe it?"

"This."

And Rouletabille handed Koupriane the message he had received that same
morning.

"Oh, oh," cried Koupriane. "You are under watch! Look out."

"I have nothing to fear; I'm not bothering myself about anything
further. Yes, we have an affair of the revolutionaries, but not of the
usual kind. The way they are going about it isn't like one of their
young men that the Central Committee arms with a bomb and who is
sacrificed in advance."

"Where are the tracks that you have traced?"

"Right up to the little Krestowsky Villa."

Koupriane bounded from his chair.

"Occupied by Boris. Parbleu! Now we have them. I see it all now. Boris,
another cracked brain! And he is engaged. If he plays the part of the
Revolutionaries, the affair would work out big for him."

"That villa," said Rouletabille