.. I say
to myself ... I say to myself, Mazeroux, that this is a devilish
mysterious little hole and that this house--Hush! Listen--"

He pushed Mazeroux into a dark corner. They had heard a noise, the
slamming of a door.

Footsteps crossed the courtyard in front of the house. The lock of the
outer gate grated. Some one appeared, and the light of a street lamp fell
full on his face.

"Dash it all," muttered Mazeroux, "it's he!"

"I believe you're right."

"It's he. Chief. Look at the black stick and the bright handle. And did
you see the eyeglasses--and the beard? What a oner you are, Chief!"

"Calm yourself and let's go after him."

The man had crossed the Boulevard Richard-Wallace and was turning into
the Boulevard Maillot. He was walking pretty fast, with his head up,
gayly twirling his stick. He lit a cigarette.

At the end of the Boulevard Maillot, the man passed the octroi and
entered Paris. The railway station of the outer circle was close by. He
went to it and, still followed by the others, stepped into a train that
took them to Auteuil.

"That's funny," said Mazeroux. "He's doing exactly what he did a
fortnight ago. This is where he was seen."

The man now went along the fortifications. In a quarter of an hour he
reached the Boulevard Suchet and almost immediately afterward the house
in which M. Fauville and his son had been murdered.

He climbed the fortifications opposite the house and stayed there for
some minutes, motionless, with his face to the front of the house. Then
continuing his road he went to La Muette and plunged into the dusk of the
Bois de Boulogne.

"To work and boldly!" said Don Luis, quickening his pace.

Mazeroux stopped him.

"What do you mean, Chief?"

"Well, catch him by the throat! There are two of us; we couldn't hope for
a better moment."

"What! Why, it's impossible!"

"Impossible? Are you afraid? Very well, I'll do it by myself."

"Look here, Chief, you're not serious!"

"Why shouldn't I be serious?"

"Because one can't arrest a man without a reason."

"Without a reason? A scoundrel like this? A murderer? What more do
you want?"

"In the absence of compulsion, of catching him in the act, I want
something that I haven't got."

"What's that?"

"A warrant. I haven't a warrant."

Mazeroux's accent was so full of conviction, and the answer struck Don
Luis Perenna as so comical, that he burst out laughing.

"You have no warrant? Poor little chap! Well, I