h the aperture formed by the removal of the masonry, a terrible
menace met their ears.

"Vengeance!" cried Piero, furiously; "vengeance on the murderess of
Carlotta!"

"Yes--vengeance shalt thou have, comrade," returned the deep, sonorous
voice of Stephano.

But scarcely were those words uttered, when the loud clanging of the
bell struck up; and the abbess exclaimed joyfully, "We are saved! we are
saved!"

CHAPTER XXXII.

THE MYSTERY OF THE CHAIR--THE CATASTROPHE.

The reader will recollect that when Flora Francatelli was released from
the chair at the bottom of the pit or well, Sister Alba had led her
along a narrow, dark passage communicating with the chamber of
penitence.

In a small dome-like cavity, hollowed out of the roof of this passage,
hung a large bell; and in a cell opening from the side of the passage
immediately beneath the dome, dwelt an old nun, who, for some dreadful
misdeed committed in her youth, had voluntarily consigned herself to the
convent of the Carmelites, and, having passed through the ordeal of the
chamber of penitence, had accepted the office of sextoness in that
department of the establishment.

It was her duty to keep the chamber of penitence clean, maintain tapers
constantly burning before the altar, supply also the cells of the
penitents themselves with lights, and toll the bell whenever occasion
required. She it was who had visited Flora's cell the first night of her
arrival at the convent, to renew the taper that burnt before her
crucifix, and to exchange the maiden's attire for the conventual garb.

This old nun it was, then, who suddenly tolled the bell, at the moment
when Piero and Stephano were menacing the abbess and Sister Alba with
their vengeance, and when the Marquis of Orsini was bearing away Flora
to the robbers' hold, that she might have the companionship of Giulia.

The way in which the old nun rang the bell was such that the inmates of
the convent would perceive it to be an alarm; and moreover, so sudden
was its startling clang, that Stephano and Piero abandoned their hold
upon the abbess and Sister Alba, and retreated a few paces, uncertain
how to act; hence the exclamation of the superior of the convent, "We
are saved! we are saved!"

But little did that stern, imperious woman know of the desperate
characters of those with whom she had now to deal. Ashamed of their
momentary hesitation, Stephano and Piero rushed on the abbess and Sister
Alba, and