While the old man said these few words in the most natural tone, and with the most careless manner, the woman behind the grating examined him with earnestness.
"Wait," answered she, after a slight pause.
The slide was again put back.
"Hum!" murmured the professor, in a low voice, "The place is well guarded."
A noise of drawing bolts and of detaching chains was heard, and the gate was half-opened—just enough to admit one person.
"Enter, then," said, in a surly tone, the woman who had at first shown herself at the grating, and who appeared to be the portress of this convent-like house.
The old man entered slowly, his hat in his hand, and bowing low.
The sight of his bald head, with but here and there a few hairs of reddish grey, appeared to give confidence to the old woman.
"Follow me," said she to him, in a peevish tone, "and replace your hat, these corridors are cold and damp."
The old man bowed, replaced his hat on his head, and, leaning on his stick, he followed the nun with that somewhat trembling step which is characteristic of persons who have considerably passed middle age.