-a packet of
letters which I value more than my life. It is possible that those
letters, if misinterpreted, will furnish a weapon against me; but no
matter. The great thing is that they should be safe. You will see. They
include documents of extreme importance. I entrust them to your
keeping--to yours alone, Monsieur le Prefet."

"Where are they?"

"The hiding-place is easily found. All you have to do is to go to the
garret above my bedroom and press on a nail to the right of the window.
It is an apparently useless nail, but it controls a hiding-place outside,
under the slates of the roof, along the gutter."

He moved away between the two men. The Prefect called them back.

"One second. Mazeroux, go up to the garret and bring me the letters."

Mazeroux went out and returned in a few minutes. He had been unable to
work the spring.

The Prefect ordered Chief Inspector Ancenis to go up with Mazeroux and to
take the prisoner, who would show them how to open the hiding-place. He
himself remained in the room with Weber, awaiting the result of the
search, and began to read the titles of the volumes piled upon the table.

They were scientific books, among which he noticed works on chemistry:
"Organic Chemistry" and "Chemistry Considered in Its Relations with
Electricity." They were all covered with notes in the margins. He was
turning over the pages of one of them, when he seemed to hear shouts.

The Prefect rushed to the door, but had not crossed the threshold when a
pistol shot echoed down the staircase and there was a yell of pain.

Immediately after came two more shots, accompanied by cries, the sound of
a struggle, and yet another shot.

Tearing upstairs, four steps at a time, with an agility not to be
expected from a man of his build, the Prefect of Police, followed by the
deputy chief, covered the second flight and came to a third, which was
narrower and steeper. When he reached the bend, a man's body, staggering
above him, fell into his arms: it was Mazeroux, wounded.

On the stairs lay another body, lifeless, that of Chief Inspector
Ancenis.

Above them, in the frame of a small doorway, stood Gaston Sauverand, with
a savage look on his face and his arm outstretched. He fired a fifth shot
at random. Then, seeing the Prefect of Police, he took deliberate aim.

The Prefect stared at that terrifying barrel levelled at his face and
gave himself up for lost. But, at that exact second, a shot was
discharged fro