Malipieri had good nerves, but for a moment he was dazed, and then, perhaps for the first time in his life, he was thoroughly frightened, for he knew that Sabina must be still asleep in his room, and in spite of his urgent request when he had left her, he did not believe that she had locked the door after all.  The first thought that flashed upon him was that Volterra had somehow discovered that she was there, and had come to find her.  There were six men in the room; he guessed that the Baron was one of those people who carry revolvers about with them, and two of the others were police soldiers, also armed with revolvers.  He was evidently at their mercy.  Short of throwing at least three of the party out of the window, nothing could avail.  Such things are done without an effort on the stage by the merest wisp of a man, but in real life one must be a Hercules or a gladiator even to attempt them.  Malipieri thought of what Sabina had said in the vault.  Had any two people ever been in such a situation before?

For one instant, his heart stood still, and he passed his hand over his eyes.

“Excuse me,” he said then, quite naturally.  “I had dressed to go to your house this morning, and I fell asleep in my chair while waiting till it should be time.  How did you get in?  And why have you brought these people with you?”

He was perfectly cool now, and the Baron regretted that he had made a forcible entrance.

“I must really apologize,” he answered.  “The porter rang yesterday evening, several times, and again this morning, but could get no answer, and as you had told me that you were going to change your quarters, we supposed that you had left and had accidentally taken the key with you.”

Malipieri did not believe a word of what he said, but the tone was very apologetic.

“The cellars are flooded,” said the porter, speaking over Volterra’s shoulder.

“I know it,” Malipieri answered.  “I was going to inform you of that this morning,” he continued, speaking to the Baron.  “I do not think that the police are necessary to our conversation,” he added, smiling at the detective.

“I beg your pardon, sir,” answered the latter, “but we are here to ask if you know anything of a grave accident to a certain Signor Sassi, who was taken from this palace unconscious, yesterday afternoon, at about a quarter to six, by a very large man, who would not give any name, nor any explanation, and who was consequently arrested.”

Malipieri did not hesitate.

“Only this much,” he replied.  “With the authority of the Senator here, who is the owner of the palace, I have been making some archaeological excavations in the cellars.  Signor Sassi was the agent—­”

“I have explained that,” interrupted the Baron, turning to the detective.  “I will assume the whole responsibility of this affair.  Signor Sassi shall be well cared for.  I shall be much obliged if you will leave us.”