He caught up Guerchard on the stairs and said, "I will come with
you, if I may, M. Guerchard. I find all these investigations
extraordinarily interesting. I have been observing M. Formery's
methods--I should like to watch yours, for a change."

"By all means," said Guerchard. "And there are several things I want
to hear about from your Grace. Of course it might be an advantage to
discuss them together with M. Formery, but--" and he hesitated.

"It would be a pity to disturb M. Formery in the middle of the
process of reconstruction," said the Duke; and a faint, ironical
smile played round the corners of his sensitive lips.

Guerchard looked at him quickly: "Perhaps it would," he said.

They went through the house, out of the back door, and into the
garden. Guerchard moved about twenty yards from the house, then he
stopped and questioned the Duke at great length. He questioned him
first about the Charolais, their appearance, their actions,
especially about Bernard's attempt to steal the pendant, and the
theft of the motor-cars.

"I have been wondering whether M. Charolais might not have been
Arsene Lupin himself," said the Duke.

"It's quite possible," said Guerchard. "There seem to be no limits
whatever to Lupin's powers of disguising himself. My colleague,
Ganimard, has come across him at least three times that he knows of,
as a different person. And no single time could he be sure that it
was the same man. Of course, he had a feeling that he was in contact