“O God, have pity on me!  I can’t die!  I can’t let my son die!  Have pity on me, I beseech Thee!”

He sprang to his feet and led Perenna to a glass-fronted case, which he rolled back on its brass castors, revealing a small safe built into the wall.

“You will find my whole story here, written up day by day for the past three years.  If anything should happen to me, revenge will be easy.”

He hurriedly turned the letters of the padlock and, with a key which he took from his pocket, opened the safe.

It was three fourths empty; but on one of the shelves, between some piles of papers, was a diary bound in drab cloth, with a rubber band round it.  He took the diary, and, emphasizing his words, said: 

“There, look, it’s all in here.  With this, the hideous business can be reconstructed....  There are my suspicions first and then my certainties....  Everything, everything ... how to trap them and how to do for them....  You’ll remember, won’t you?  A diary bound in drab cloth....  I’m putting it back in the safe.”

Gradually his calmness returned.  He pushed back the glass case, tidied a few papers, switched on the electric lamp above his bed, put out the lights in the middle of the ceiling, and asked Don Luis and Mazeroux to leave him.

Don Luis, who was walking round the room and examining the iron shutters of the two windows, noticed a door opposite the entrance door and asked the engineer about it.

“I use it for my regular clients,” said Fauville, “and sometimes I go out that way.”

“Does it open on the garden?”

“Yes.”

“Is it properly closed?”

“You can see for yourself; it’s locked and bolted with a safety bolt.  Both keys are on my bunch; so is the key of the garden gate.”

He placed the bunch of keys on the table with his pocket-book and, after first winding it, his watch.

Don Luis, without troubling to ask permission, took the keys and unfastened the lock and the bolt.  A flight of three steps brought him to the garden.  He followed the length of the narrow border.  Through the ivy he saw and heard the two policemen pacing up and down the boulevard.  He tried the lock of the gate.  It was fastened.

“Everything’s all right,” he said when he returned, “and you can be easy.  Good-night.”

“Good-night,” said the engineer, seeing Perenna and Mazeroux out.

Between his study and the passage were two doors, one of which was padded and covered with oilcloth.  On the other side, the passage was separated from the hall by a heavy curtain.

“You can go to sleep,” said Perenna to his companion.  “I’ll sit up.”

“But surely, Chief, you don’t think that anything’s going to happen!”

“I don’t think so, seeing the precautions which we’ve taken.  But, knowing Inspector Verot as you did, do you think he was the man to imagine things?”