But at least he could prevent her from coming in, for he could lock the entrance to the small room.  As he reached the end of his walk he turned the key and put it into his pocket.  The detective turned round sharply and Volterra moved his head at the sound.

“Why do you do that?” he asked, in a tone of annoyance.

“Because no one shall go in, while I have the key,” Malipieri answered.

“I must go in, sooner or later,” said the detective, “I can wait all day, and all night, if you please, for I shall not use force where a lady is concerned.  But I must see that room.”

Like all such men, he was obstinate, when he believed that he was doing his duty.  Malipieri looked from him to Volterra, and back again, and suddenly made up his mind.  He preferred the detective, of the two, if he must trust any one, the more so as the latter probably did not know Sabina by sight.

“If you will be so kind as to stay there, in that armchair,” he said to Volterra, “I will see what I can do to hasten matters.  Will you?”

“Certainly.  I am very comfortable here.”  The Baron laughed a little.

“Then,” said Malipieri, turning to the detective, “kindly come with me, and I will explain as far as I can.”

He took the key from his pocket again, and opened the door of the small room, let in the detective and shut it after him without locking it.  He had hardly made up his mind what to say, but he knew what he wished.

“This is a very delicate affair,” he began in a whisper.  “I will see whether the lady is awake.”

He went to the door of the bedroom on tiptoe and listened.  Not a sound reached him.  The room was quite out of hearing of the rest of the apartment, and Sabina, accustomed as she was to sleep eight hours without waking, was still resting peacefully.  Malipieri came back noiselessly.

“She is asleep,” he whispered.  “Will you not take my word for it that there is nothing to be found in the room which can have the least connection with Sassi’s accident?”

The detective shook his head gravely, and raised his eyebrows, while he shut his eyes, as some men do when they mean that nothing can convince them.

“I advise you to go in and wake your wife,” he whispered, still very politely.  “She can wrap herself up and sit in a chair while I look in.”

“That is impossible.  I cannot go in and wake her.”

The detective looked surprised, and was silent for a moment.

“This is a very strange situation,” he muttered.  “A man who dares not go into his wife’s room when she is asleep—­I do not understand.”

“I cannot explain,” answered Malipieri, “but it is altogether impossible.  I ask you to believe me, on my oath, that you will find nothing in the room.”

“I have already told you, sir, that I must fulfil the formalities, whatever I may wish to believe.  And it is my firm belief that Signor Sassi came by the injuries of which he may possibly die, somewhere in this apartment, yesterday afternoon.  My reputation is at stake, and I am a government servant.  To oblige you, I will wait an hour, but if the lady is not awake then, I shall go and knock at that door and call until she answers.  It would be simpler if you would do it yourself.  That is all, and you must take your choice.”