At that exact moment a shot rang out. The dog turned a complete somersault, recovered its feet, tore the ground and then lay down, giving a number of hoarse, breathless howls, which ended in a dull moan and an indistinct gurgling. And that was all.

"Dead," said Lupin, who had hastened up at once, prepared, if necessary, to fire his revolver a second time.

The girl had risen and stood pale, still staggering. She looked in great surprise at this man whom she did not know and who had saved her life; and she whispered:

"Thank you.... I have had a great fright.... You were in the nick of time.... I thank you, monsieur."

Lupin took off his hat:

"Allow me to introduce myself, mademoiselle.... My name is Paul Daubreuil.... But before entering into any explanations, I must ask for one moment...."

He stooped over the dog's dead body and examined the chain at the part where the brute's effort had snapped it:

"That's it," he said, between his teeth. "It's just as I suspected. By Jupiter, things are moving rapidly!... I ought to have come earlier."

Returning to the girl's side, he said to her, speaking very quickly:

"Mademoiselle, we have not a minute to lose. My presence in these grounds is quite irregular. I do not wish to be surprised here; and this for reasons that concern yourself alone. Do you think that the report can have been heard at the house?"