“You must not be frightened, Mademoiselle.  If you obey me implicitly, you will have nothing to fear.”

She did not reply and he saw that she still mistrusted him.  And he almost rejoiced at the thought that he would compel her to believe in him.

“Listen to me,” he said to Sauverand.  “In case I should not succeed after all, there are still several things which you must explain.”

“What are they?” asked Sauverand, who had lost none of his coolness.

Then, collecting all his riotous thoughts, resolved to omit nothing, but at the same time to speak only what was essential, Don Luis asked, in a calm voice: 

“Where were you on the morning before the murder, when a man carrying an ebony walking-stick and answering to your description entered the Cafe du Pont-Neuf immediately after Inspector Verot?”

“At home.”

“Are you sure that you did not go out?”

“Absolutely sure.  And I am also sure that I have never been to the Cafe du Pont-Neuf, of which I had never even heard.”

“Good.  Next question.  Why, when you learned all about this business, did you not go to the Prefect of Police or the examining magistrate?  It would have been simpler for you to give yourself up and tell the exact truth than to engage in this unequal fight.”

“I was thinking of doing so.  But I at once realized that the plot hatched against me was so clever that no bare statement of the truth would have been enough to convince the authorities.  They would never have believed me.  What proof could I supply?  None at all—­whereas, on the other hand, the proofs against us were overwhelming and undeniable.  Were not the marks of the teeth evidence of Marie’s undoubted guilt?  And were not my silence, my flight, the shooting of Chief Inspector Ancenis so many crimes?  No, if I would rescue Marie, I must remain free.”

“But she could have spoken herself?”

“And confessed our love?  Apart from the fact that her womanly modesty would have prevented her, what good would it have done?  On the contrary, it meant lending greater weight to the accusation.  That was just what happened when Hippolyte Fauville’s letters, appearing one by one, revealed to the police the as yet unknown motives of the crimes imputed to us.  We loved each other.”

“How do you explain the letters?”

“I can’t explain them.  We did not know of Fauville’s jealousy.  He kept it to himself.  And then, again, why did he suspect us?  What can have put it into his head that we meant to kill him?  Where did his fears, his nightmares, come from?  It is a mystery.  He wrote that he had letters of ours in his possession:  what letters?”

“And the marks of the teeth, those marks which were undoubtedly made by Mme. Fauville?”

“I don’t know.  It is all incomprehensible.”

“You don’t know either what she can have done after leaving the opera between twelve and two in the morning?”