What was hard to understand was that Volterra should know how far the work had gone before Malipieri had told him anything about it.  That he did know, could hardly be doubted.  He had practically betrayed the fact by the mistake he had made in assuring himself that Malipieri was willing to leave the house, before even questioning him as to the progress made since they had last met.  He had been a little too eager to get rid of the helper he no longer needed.  It did not even occur to Malipieri that Masin could have betrayed him, yet so far as it was possible to judge, Masin was the only living man who had looked into the underground chamber.  As he walked home, he recalled the conversation from beginning to end, and his conviction was confirmed.  Volterra had been in a bad temper, nervous, a little afraid of the result and therefore inclined to talk in a rough and bullying tone.  As soon as he had ascertained that Malipieri was not going to oppose him, he had become oily to obsequiousness.

On his part Malipieri had accepted everything Volterra proposed, for two reasons.  In the first place he would not for the world have had the financier think that he wanted a share of the treasure, or any remuneration for what he had done.  Secondly, he knew that possession is nine points of the law, and that if anything could ever be obtained for Sabina it would not be got by making a show of violent opposition to the Baron’s wishes.  If Malipieri had refused to leave his lodging in the palace, Volterra could have answered by filling the house with people in his own employ, or by calling in government architects, archaeologists and engineers, and taking the whole matter out of Malipieri’s hands.

The first thing to be ascertained was, who had entered the vaults and reported the state of the work to Volterra.  Malipieri might have suspected the porter himself, for it was possible that there might be another key to the outer entrance of the cellar; but there was a second door further in, to which Masin had put a patent padlock, and even Masin had not the key to that.  The little flat bit of steel, with its irregular indentations, was always in Malipieri’s pocket.  As he walked, he felt for it, and it was in its place, with his silver pencil-case and the small penknife he always carried for sharpening pencils.

The porter could not possibly have picked that lock; indeed, scarcely any one could have done so without injuring it, and Malipieri had locked it himself at about seven o’clock that evening.  Even if the porter could have got in by any means, Malipieri doubted whether he could have reached the inner chamber of the vaults.  There was some climbing to be done, and the man was old and stiff in the joints.  The place was not so easy to find as might have been supposed, either, after the first breach in the Roman wall was past.  Malipieri intended to improve the passage the next morning, in order to make it more practicable for Sabina.