“I am just going on my usual nocturnal round,” he said abruptly. “Come with me, citizen de Batz.”

A certain grim humour was apparent in his face as he proffered this invitation, which sounded like a rough command. As de Batz seemed to hesitate he nodded peremptorily to him to follow. Already he had gone into the hall and picked up his lanthorn. From beneath his waistcoat he drew forth a bunch of keys, which he rattled impatiently, calling to his friend to come.

“Come, citizen,” he said roughly. “I wish to show you the one treasure in this house which your d—d fingers must not touch.”

Mechanically de Batz rose at last. He tried to be master of the terror which was invading his very bones. He would not own to himself even that he was afraid, and almost audibly he kept murmuring to himself that he had no cause for fear.

Heron would never touch him. The spy’s avarice, his greed of money were a perfect safeguard for any man who had the control of millions, and Heron knew, of course, that he could make of this inveterate plotter a comfortable source of revenue for himself. Three weeks would soon be over, and fresh bargains could be made time and again, while de Batz was alive and free.

Heron was still waiting at the door, even whilst de Batz wondered what this nocturnal visitation would reveal to him of atrocity and of outrage. He made a final effort to master his nervousness, wrapped his cloak tightly around him, and followed his host out of the room.

[ [!-- H2 anchor --] ]

CHAPTER VII. THE MOST PRECIOUS LIFE IN EUROPE

Once more he was being led through the interminable corridors of the gigantic building. Once more from the narrow, barred windows close by him he heard the heart-breaking sighs, the moans, the curses which spoke of tragedies that he could only guess.

Heron was walking on ahead of him, preceding him by some fifty metres or so, his long legs covering the distances more rapidly than de Batz could follow them. The latter knew his way well about the old prison. Few men in Paris possessed that accurate knowledge of its intricate passages and its network of cells and halls which de Batz had acquired after close and persevering study.