Certainly it would have been impossible to have invented a better place in which to hide any number of prisoners than the immense cellars and vaults and dark holes of all sorts, that ran underneath. The building itself was more like a village than a house, and, since its foundation, had been constantly added to and altered, so that it was full of irregularities and steps up and down and roofs at different heights, and passages which once led to something but were now blocked up. On one side of the garden, whose magnificent chestnut trees were the pride of the nuns, stood small houses in which lived noble ladies retired from the world, but free from vows. There was besides a very large vegetable garden for the use of the convent, which at this time contained about a hundred and thirty people. It was possible, if you stood on tiptoe, to snatch a glimpse through the grating of melons or grapes or feathery pinks, but the door was not easy to climb, and only two or three of the bolder girls had ever managed to penetrate into the enclosure and taste these forbidden joys.
The legend of the concealed prisoner had been handed on from generation to generation of school girls, as well as the terrors which were half a joy, that thrilled through them as they crept along the narrow passages, ending no one knew where—perhaps in the Catacombs, perhaps in the baths of Julian, perhaps outside Paris itself! Who could tell? Could life have any feeling more exciting in store than the sensation that at any moment your feet might meet the empty air, and that you might fall into one of those terrible pits common in castles of the Middle Ages, known by the evil name of oubliettes or holes of forgetfulness? And many of these dangers were not at all imaginary, whatever the 'prisoner' might be.
It was the knowledge of the heavy punishments that would fall on their heads in case of discovery that made it a point of honour with the demons to risk everything in order to explore this underground world. Very few, however, gained an entrance to these vaults during their school lives, and only then after years of patience and perseverance. The memory of these heroines was kept green, and their names whispered reverently 'to encourage the rest.'
In Aurore's day the question had come up again—the burning question of how to get into the underground world. Not by the main door which led to it, that was clear; for close by were the kitchens, where nuns passed continually! But if the main door was barred, there must be a hundred other doors or walled-up staircases, by which you could get there; and if these failed, there was always the roof.
Now, the very last thought that would occur to most people, if they want to penetrate into an underground passage, is to go first on to the roof; but then they are not school girls, and have forgotten all about these things, if, indeed, they ever knew them. To Aurore and her friends it was a matter of everyday knowledge that 'the longest way round is the shortest way home.' Had not Aurore sat breathless for days together over Mrs. Radcliffe's Mysteries of Udolpho, and her companions lain awake trembling at the recollections of Scotch or Irish ancestral ghosts?
Why, even in the convent, where the great dormitories were filled with girls and the terrors of loneliness were unknown, did they not shudder sometimes in the dark in the certainty that they caught the echo of the sighs, the groans, the clanking of chains of the victim?
As to whether it was always the same victim who had to be rescued, or whether in every generation a fresh victim was somehow mysteriously supplied, nobody inquired and nobody minded.
On the never-to-be-forgotten evening of Aurore's initiation into the company of the demons, she was conducted by the rest of the band into the oldest and most irregular part of the convent. At length they found themselves standing on a gangway with a wooden railing, ending in a little room, from which there was no outlet. By the light of their single taper they beheld a staircase below them, also with a wooden railing, and protected at the top by a strong oaken door. In order to get on to the staircase it was necessary to drop from one balustrade to the other—and the more experienced of the explorers strongly suspected that both of them were worm-eaten—while the staircase hung over black depths which no eye could penetrate.