Ganimard locked his assistants in the gallery, carried away the keys, and said to the baron:

“And now, to our post.”

He had chosen for himself a small room located in the thick outer wall, between the two principal doors, and which, in former years, had been the watchman’s quarters. A peephole opened upon the bridge; another on the court. In one corner, there was an opening to a tunnel.

“I believe you told me, Monsieur le Baron, that this tunnel is the only subterranean entrance to the castle and that it has been closed up for time immemorial?”

“Yes.”

“Then, unless there is some other entrance, known only to Arsène Lupin, we are quite safe.”

He placed three chairs together, stretched himself upon them, lighted his pipe and sighed: