e, and for a space there would be no
light save that of the stars.

Constanza laid her finger upon her lips, and made a sign demanding
caution. Gaston understood that he was warned not to speak, and to tread
cautiously, which he did, stealing along after his fairy-like companion,
and striving to emulate her dainty, bird-like motions. He could see by
the glint of water that they were skirting along beside the moat, but he
had never approached so near to it before, and he knew not where they
were going.

Some men might have feared treachery, but such an idea never entered
Gaston's head. Little as he knew of his companion, he knew that she was
true and loyal, that she was beloved by him, and that her heart was
already almost won.

Presently the girl stopped and laid her hand upon his arm.

"This is the place," she whispered. "Come very softly to the water's
edge, and I will show you the dark hole opposite, just above the
waterline, where entrance can be made. There be no loopholes upon this
side of the Tower, and no watchman is needed where there be no foothold
for man to scale the wall beneath.

"Look well across the moat. Seest thou yon black mark, that looks no
larger than my hand? That is the entrance to a tunnel which slopes
upward until it reaches a narrow doorway in the thickness of the solid
wall whereby the underground chamber may be reached. Once there, thou
wilt see let into the wall a great wheel with iron spokes projecting
from it. Set that wheel in motion, and a portion of the flooring of the
chamber above will descend. When it has reached the ground, thou canst
ascend by reversing the wheel, leaving always some one in the chamber
below to work the wheel, which will enable thee to bring thy brother
down again. That accomplished, all that remains will be to creep again
through the narrow passage to the moat and swim across once more. Thou
canst swim?"

"Ay, truly. Raymond and I have been called fishes from our childhood. We
swam in the great mill pool almost ere we could well run alone. Many of
my stout fellows behind are veritable water rats. If my brother be not
able to save himself, there will be a dozen stout arms ready to support
him across the moat.

"And what will be the hour when this attempt must be made? What if the
very moment I reached my brother his jailer should come to him, and the
alarm be given through the Castle ere we could get him thence?"

"That it must be my office to prevent,"