"I believe some imaginative Parisian journalist fixed that sobriquet on
him, in recognition of the theory upon which, apparently, he operated."

"And that was--?"

"That a criminal, at least a thief, to be successful must be absolutely
anonymous and friendless; in which case nobody can betray him. As
madame probably understands, criminals above a certain level of
intelligence are seldom caught by the police except through the
treachery of accomplices. The Lone Wolf seems to have exercised a fair
amount of ingenuity and prudence in making his coups; and inasmuch as
he had no confederates, not a living soul in his confidence, there was
no one who could sell him to the authorities."

"Still, in the end--?"

"Oh, no, madame. He was never caught. He simply ceased to thieve."

"I wonder why..."

"I believe because he fell in love and considered good faith with the
object of his affections incompatible with a career of crime."

"So he gave up crime. How romantic! And the woman: did she appreciate
the sacrifice?"

"While she lived, yes, madame. Or so they say. Unfortunately, she
died."

"And then--?"