be numbered
among the most terrible that he had yet sustained.

He knew the Prefect's reputation, his experience, his tenacity, and the
keen pleasure which he took in conducting important inquiries and in
personally pushing them to a conclusion before placing them in the
magistrate's hands; and he also knew all the professional qualities of
the chief detective, and all the subtlety, all the penetrating logic
possessed by the examining magistrate.

The Prefect of Police himself directed the attack. He did so in a
straightforward fashion, without beating about the bush, and in a rather
harsh voice, which had lost its former tone of sympathy for Don Luis. His
attitude also was more formal and lacked that geniality which had struck
Don Luis on the previous day.

"Monsieur," he said, "circumstances having brought about that, as the
residuary legatee and representative of Mr. Cosmo Mornington, you spent
the night on this ground floor while a double murder was being committed
here, we wish to receive your detailed evidence as to the different
incidents that occurred last night."

"In other words, Monsieur le Prefet," said Perenna, replying directly to
the attack, "in other words, circumstances having brought about that you
authorized me to spend the night here, you would like to know if my
evidence corresponds at all points with that of Sergeant Mazeroux?"

"Yes."

"Meaning that the part played by myself strikes you as suspicious?"

M. Desmalions hesitated. His eyes met Don Luis's eyes; and he was visibly
impressed by the other's frank glance. Nevertheless he replied, plainly
and bluntly:

"It is not for you to ask me questions, Monsieur."

Don Luis bowed.

"I am at your orders, Monsieur le Prefet."

"Please tell us what you know."

Don Luis thereupon gave a minute account of events, after which M.
Desmalions reflected for a few moments and said:

"There is one point on which we want to be informed. When you entered
this room at half-past two this morning and sat down beside M. Fauville,
was there nothing to tell you that he was dead?"

"Nothing, Monsieur le Prefet. Otherwise, Sergeant Mazeroux and I would
have given the alarm."

"Was the garden door shut?"

"It must have been, as we had to unlock it at seven o'clock."

"With what?"

"With the key on the bunch."

"But how could the murderers, coming from the outside, have opened it?"

"With false keys."

"Have you a proof which allows you to suppos