It was no wonder that he unconsciously struck faster as he worked, and at first he felt himself stronger than before, as men do when they are almost despairing.  The sweat stood out on his forehead, and his hands tingled, when he drew back the iron to clear away the chips.  He worked harder and harder.

The queer little tune did not ring in his head now, for he could think of nothing but Sabina and of what was to become of her, even if he succeeded in saving her life.  It was almost impossible that such a strange adventure should remain a secret, and, being once known, the injury to the girl might be irreparable.  He hated himself for having brought her to the place.  Yet, as he thought it over, he knew that he would have done it again.

It had seemed perfectly safe.  Any one could have seen that the water had not risen in the well for many years.  Day after day, for a long time, he and Masin had worked in the vaults in perfect safety.  The way to the statues had been made so easy that only a timid old man like Sassi could have found it impassable.  There had been absolutely no cause to fear that after fifty or sixty years the course of the water should be affected, and the chances against such an accident happening during that single hour of Sabina’s visit were as many millions to one.  His motive in bringing her had been quixotic, no doubt, but good and just, and so far as Sabina’s reputation was concerned, Sassi’s presence had constituted a sufficient social protection.

He hammered away at the bricks furiously, and the cavity grew deeper and wider.  Surely he had made a mistake at first in wishing to husband his strength too carefully.  If he had worked from the beginning as he was working now, he would have made the breach by this time.

Unless that were impossible; unless, after all, he had struck the end of a cross wall and was working through the length of it instead of through its thickness.  The fear of such a misfortune took possession of him, and he laid down his crowbar to examine the wall carefully.  There was one way of finding out the truth, if he could only get light enough; no mason that ever lived would lay his bricks in any way except lengthwise along each course.  If he had struck into a cross wall, he must be demolishing the bricks from their ends instead of across them, and he could find out which way they lay at the end of the cavity, if he could make the light of the lantern shine in as far as that.  The depth was more than five feet now, and his experience told him that even in the construction of a mediaeval palace the walls above the level of the ground were very rarely as thick as that, when built of good brick and cement like this one.

When he took up his lantern, he was amazed at what he had done in less than four hours; if he had been told that an ordinary man had accomplished anything approaching to it in that time, he would have been incredulous.  He had hardly realized that he had made a hole big enough for him to work in, kneeling on one knee, and bracing himself with the other foot.