evidently the Prefect and the magistrates from the public
prosecutor's office.

Don Luis took Mazeroux by the arm.

"There's only one way out of it, Alexandre! Don't say you went to sleep."

"I must, Chief."

"You silly ass!" growled Don Luis. "How is it possible to be such an ass!
It's enough to disgust one with honesty. What am I to do, then?"

"Discover the culprit, Chief."

"What! ... What are you talking about?"

Mazeroux, in his turn, took him by the arm and, clutching him with a sort
of despair, said, in a voice choked with tears:

"Discover the culprit, Chief. If not, you're done for ... that's
certain ... the Prefect told me so. ... The police want a
culprit ... they want him this evening.... One has got to be
found.... It's up to you to find him."

"What you have, Alexandre, is a merry wit."

"It's child's play for you, Chief. You have only to set your mind to it."

"But there's not the least clue, you ass!"

"You'll find one ... you must ... I entreat you, hand them over
somebody.... It would be more than I could bear if you were arrested.
You, the chief, accused of murder! No, no.... I entreat you, discover the
criminal and hand him over.... You have the whole day to do it in...and
Lupin has done greater things than that!"

He was stammering, weeping, wringing his hands, grimacing with every
feature of his comic face. And it was really touching, this grief, this
dismay at the approach of the danger that threatened his master.

M. Desmalions's voice was heard in the hall, through the curtain that
closed the passage. A third motor car stopped on the boulevard, and a
fourth, both doubtless laden with policemen.

The house was surrounded, besieged.

Perenna was silent.

Beside him, anxious-faced, Mazeroux seemed to be imploring him.

A few seconds elapsed.

Then Perenna declared, deliberately:

"Looking at things all round, Alexandre, I admit that you have seen the
position clearly and that your fears are fully justified. If I do not
manage to hand over the murderer or murderers of Hippolyte Fauville and
his son to the police in a few hours from now, it is I, Don Luis Perenna,
who will be lodged in durance vile on the evening of this Thursday, the
first of April."

CHAPTER FOUR

THE CLOUDED TURQUOISE

It was about nine o'clock in the morning when the Prefect of Police
entered the study in which the incomprehensible tragedy of that double
murder had been enacted.

He did n