“Lord, what a time you take!” growled Don Luis.

Mazeroux plunged both hands into the crowd of papers that encumbered the iron shelf.

“Well, Mazeroux, hand it over.”

“What?”

“The diary.”

“I can’t Chief.”

“What’s that?”

“It’s gone.”

Don Luis stifled an oath.  The drab-cloth diary, which the engineer had placed in the safe before their eyes, had disappeared.

Mazeroux shook his head.

“Dash it all!  So they knew about that diary!”

“Of course they did; and they knew plenty of other things besides.  We’ve not seen the end of it with those fellows.  There’s no time to lose.  Ring up!”

Mazeroux did so and soon received the answer that M. Desmalions was coming to the telephone.  He waited.

In a few minutes Perenna, who had been walking up and down, examining different objects in the room, came and sat down beside Mazeroux.  He seemed thoughtful.  He reflected for some time.  But then, his eyes falling on the fruit dish, he muttered: 

“Hullo!  There are only three apples instead of four.  Then he ate the fourth.”

“Yes,” said Mazeroux, “he must have eaten it.”

“That’s funny,” replied Perenna, “for he didn’t think them ripe.”

He was silent once more, sat leaning his elbows on the table, visibly preoccupied; then, raising his head, he let fall these words: 

“The murder was committed before we entered the room, at half-past twelve exactly.”

“How do you know, Chief?”

“M.  Fauville’s murderer or murderers, in touching the things on the table, knocked down the watch which M. Fauville had placed there.  They put it back; but the fall had stopped it.  And it stopped at half-past twelve.”

“Then, Chief, when we settled ourselves here, at two in the morning, it was a corpse that was lying beside us and another over our heads?”

“Yes.”

“But how did those devils get in?”

“Through this door, which opens on the garden, and through the gate that opens on the Boulevard Suchet.”

“Then they had keys to the locks and bolts?”

“False keys, yes.”

“But the policemen watching the house outside?”

“They are still watching it, as that sort watch a house, walking from point to point without thinking that people can slip into a garden while they have their backs turned.  That’s what took place in coming and going.”

Sergeant Mazeroux seemed flabbergasted.  The criminals’ daring, their skill, the precision of their acts bewildered him.

“They’re deuced clever,” he said.

“Deuced clever, Mazeroux, as you say; and I foresee a tremendous battle.  By Jupiter, with what a vim they set to work!”

The telephone bell rang.  Don Luis left Mazeroux to his conversation with the Prefect, and, taking the bunch of keys, easily unfastened the lock and the bolt of the door and went out into the garden, in the hope of there finding some trace that should facilitate his quest.