?

Perenna went up to him and pressed gently on the detective's
outstretched arm.

"Prefect's orders?" he asked.

"Yes," muttered the sergeant, uncomfortably.

"Orders to keep me here until he comes?"

"Yes."

"And if I betrayed an intention of leaving, to prevent me?"

"Yes."

"By every means?"

"Yes."

"Even by putting a bullet through my skin?"

"Yes."

Perenna reflected; and then, in a serious voice:

"Would you have fired, Mazeroux?"

The sergeant lowered his head and said faintly:

"Yes, Chief."

Perenna looked at him without anger, with a glance of affectionate
sympathy; and it was an absorbing sight for him to see his former
companion dominated by such a sense of discipline and duty. Nothing was
able to prevail against that sense, not even the fierce admiration, the
almost animal attachment which Mazeroux retained for his master.

"I'm not angry, Mazeroux. In fact, I approve. Only you must tell me the
reason why the Prefect of Police--"

The detective did not reply, but his eyes wore an expression of such
sadness that Don Luis started, suddenly understanding.

"No," he cried, "no!... It's absurd ... he can't have thought
that!... And you, Mazeroux, do you believe me guilty?"

"Oh, I, Chief, am as sure of you as I am of myself!... You don't take
life!... But, all the same, there are things ... coincidences--"

"Things ... coincidences ..." repeated Don Luis slowly.

He remained pensive; and, in a low voice, he said:

"Yes, after all, there's truth in what you say.... Yes, it all fits
in.... Why didn't I think of it?... My relations with Cosmo Mornington,
my arrival in Paris in time for the reading of the will, my insisting on
spending the night here, the fact that the death of the two Fauvilles
undoubtedly gives me the millions.... And then ... and then ... why, he's
absolutely right, your Prefect of Police!... All the more so as.... Well,
there, I'm a goner!"

"Come, come, Chief!"

"A dead-goner, old chap; you just get that into your head. Not as Arsene
Lupin, ex-burglar, ex-convict, ex-anything you please--I'm unattackable
on that ground--but as Don Luis Perenna, respectable man, residuary
legatee, and the rest of it. And it's too stupid! For, after all, who
will find the murderers of Cosmo, Verot, and the two Fauvilles, if they
go clapping me into jail?"

"Come, come, Chief--"

"Shut up! ... Listen!"

A motor car was stopping on the boulevard, followed by another. It
was