This tedious explanation of a rather complicated construction has been necessary to explain what afterwards happened.  Reducing it to its simplest terms, it becomes clear that if the water rose, a person in the passage, or anywhere beyond the overflow shaft, could not possibly get back through the well, though he would apparently be safe from drowning if he stayed where he was; and to the best of Malipieri’s knowledge there was no other way out.  Any one caught there would have to wait till the water subsided, and if that did not happen he would starve to death.

The two men stood still and listened.  They could still distinguish the faint gurgling of the water, very far off, but that was all.

“I believe you heard a rat,” said Malipieri, discontentedly, after a long pause.

“Rats do not carry English wax matches,” observed Masin.

“They eat them when they can find them,” answered Malipieri.  “They carry them off, and hide them, and drop them, too.  And a big rat running away makes a noise very like a man’s footsteps.”

“That is true,” assented Masin.  “There were many of them in the prison, and I sometimes thought they were the keepers when I heard them at night.”  “At all events, we will go to the end,” said Malipieri, beginning to walk down the inclined way, and carrying his lantern low, so as not to be dazzled by the light.

Masin followed closely, grasping his drilling-iron, and still expecting to use it.  The end of the passage had once been walled up, but they had found the fragments of brick and mortar lying much as they had fallen when knocked away.  It was impossible to tell from which side the obstacle had been destroyed.

Going further, they stepped upon the curve of a tunnel vault, and were obliged to stoop low to avoid striking against another overhead.  The two vaults had been carefully constructed, one outside the other, leaving a space of about five feet between them.  The one under their feet covered the inner chamber in which Malipieri had seen the bronze statue.  He and Masin had made a hole a little on one side of the middle, in order not to disturb the keystones, working very carefully lest any heavy fragments should fall through; for they had at once been sure that if any thing was to be found, it must be concealed in that place.  Before making the opening, they had thoroughly explored the dark curved space from end to end and from side to side, but could discover no aperture.  The inner vault had never been opened since it had been built.

Malipieri, reconstructing the circumstances of the accident in the last century, came to the conclusion that the mason who had been drowned had been already between the vaults, when some of the men behind had discovered that the water was rising in the well, and that they had somehow got out in time, but that their unfortunate companion had come back too late, or had perished while trying to break his way out by the