The magistrate eagerly seized the piece of kid.

It had evidently come from a glove.

“You took care, I hope, M. Martin,” said M. Daburon, “not to attract attention at the house where you made this investigation?”

“Certainly, sir.  I first of all examined the exterior of the wall at my leisure.  After that, leaving my hat at a wine shop round the corner, I called at the Marchioness d’Arlange’s house, pretending to be the servant of a neighbouring duchess, who was in despair at having lost a favourite, and, if I may so speak, an eloquent parrot.  I was very kindly given permission to explore the garden; and, as I spoke as disrespectfully as possible of my pretended mistress they, no doubt, took me for a genuine servant.”

“You are an adroit and prompt fellow, M. Martin,” interrupted the magistrate.  “I am well satisfied with you; and I will report you favourably at headquarters.”

He rang his bell, while the detective, delighted at the praise he had received, moved backwards to the door, bowing the while.

Albert was then brought in.

“Have you decided, sir,” asked the investigating magistrate without preamble, “to give me a true account of how you spent last Tuesday evening?”

“I have already told you, sir.”

“No, sir, you have not; and I regret to say that you lied to me.”

Albert, at this apparent insult, turned red, and his eyes flashed.

“I know all that you did on that evening,” continued the magistrate, “because justice, as I have already told you, is ignorant of nothing that it is important for it to know.”

Then, looking straight into Albert’s eyes, he continued slowly:  “I have seen Mademoiselle Claire d’Arlange.”

On hearing that name, the prisoner’s features, contracted by a firm resolve not to give way, relaxed.

It seemed as though he experienced an immense sensation of delight, like a man who escapes almost by a miracle from an imminent danger which he had despaired of avoiding.  However, he made no reply.

“Mademoiselle d’Arlange,” continued the magistrate, “has told me where you were on Tuesday evening.”

Albert still hesitated.

“I am not setting a trap for you,” added M. Daburon; “I give you my word of honour.  She has told me all, you understand?”

This time Albert decided to speak.

His explanations corresponded exactly with Claire’s; not one detail more.  Henceforth, doubt was impossible.

Mademoiselle d’Arlange had not been imposed upon.  Either Albert was innocent, or she was his accomplice.

Could she knowingly be the accomplice of such an odious crime?  No; she could not even be suspected of it.

But who then was the assassin?

For, when a crime has been committed, justice demands a culprit.

“You see, sir,” said the magistrate severely to Albert, “you did deceive me.  You risked your life, sir, and, what is also very serious, you exposed me, you exposed justice, to commit a most deplorable mistake.  Why did you not tell me the truth at once?”