The search continued.  Don Luis had gradually assumed its management; and it was he who, so to speak, inspired Weber to ring at this or that door and to question this or that person.

At eleven o’clock the hunt still remained fruitless; and Don Luis was the victim of an increasing and irritating restlessness.  But, shortly after midnight, a shrill whistle drew all the men to the eastern extremity of the island, at the end of the Quai d’Anjou.

Two detectives stood waiting for them, surrounded by a small crowd of onlookers.  They had just learned that, some distance farther away, on the Quai Henri IV, which does not form part of the island, a motor car had pulled up outside a house, that there was the noise of a dispute, and that the cab had subsequently driven off in the direction of Vincennes.

They hastened to the Quai Henri IV and at once found the house.  There was a door on the ground floor opening straight on the pavement.  The taxi had stopped for a few minutes in front of this door.  Two persons, a woman and a man leading her along, had left the ground floor flat.  When the door of the taxi was shut, a man’s voice had shouted from the inside: 

“Drive down the Boulevard Saint-Germain and along the quays.  Then take the Versailles Road.”

But the porter’s wife was able to furnish more precise particulars.  Puzzled by the tenant of the ground floor, whom she had only seen once, in the evening, who paid his rent by checks signed in the name of Charles and who but very seldom came to his apartment, she had taken advantage of the fact that her lodge was next to the flat to listen to the sound of voices.  The man and the woman were arguing.  At one moment the man cried, in a louder tone: 

“Come with me, Florence.  I insist upon it; and I will give you every proof of my innocence to-morrow morning.  And, if you nevertheless refuse to become my wife, I shall leave the country.  All my preparations are made.”

A little later he began to laugh and, again raising his voice, said: 

“Afraid of what, Florence?  That I shall kill you perhaps?  No, no, have no fear—­”

The portress had heard nothing more.  But was this not enough to justify every alarm?

Don Luis caught hold of the deputy chief: 

“Come along!  I knew it:  the man is capable of anything.  It’s the tiger!  He means to kill her!”

He rushed outside, dragging the deputy toward the two police motors waiting five hundred yards down.  Meanwhile, Mazeroux was trying to protest: 

“It would be better to search the house, to pick up some clues—­”

“Oh,” shouted Don Luis, increasing his pace, “the house and the clues will keep! ...  But he’s gaining ground, the ruffian—­and he has Florence with him—­and he’s going to kill her!  It’s a trap! ...  I’m sure of it—­”

He was shouting in the dark, dragging the two men along with irresistible force.