"MONSIEUR LE PRÉFET:
"A great danger is hanging over my head and over the head of my son. Death is approaching apace. I shall have to-night, or to-morrow morning at the latest, the proofs of the abominable plot that threatens us. I ask leave to bring them to you in the course of the morning. I am in need of protection and I call for your assistance.
"Permit me to be, etc. FAUVILLE."
"No other designation?" asked Perenna. "No letter-heading?"
"None. But there is no mistake. Inspector Vérot's declarations agree too evidently with this despairing appeal. It is clearly M. Fauville and his son who are to be murdered to-night. And the terrible thing is that, as this name of Fauville is a very common one, it is impossible for our inquiries to succeed in time."
"What, Monsieur le Préfet? Surely, by straining every nerve—"
"Certainly, we will strain every nerve; and I shall set all my men to work. But observe that we have not the slightest clue."
"Oh, it would be awful!" cried Don Luis. "Those two creatures doomed to death; and we unable to save them! Monsieur le Préfet, I ask you to authorize me—"
He had not finished speaking when the Prefect's private secretary entered with a visiting-card in his hand.
"Monsieur le Préfet, this caller was so persistent…. I hesitated—"