he loved had sent him
and he never guessed the reason of that keepsake. Lupin discovered
everything, on the other hand--and took it."

"Took what?"

"The document, of course! The document written by Louis XVI.; and it is
that which I held in my hands. The same appearance, the same shape, the
same red seals. I understand why Lupin would not leave me a document
which I could turn to account by merely examining the paper, the seals
and so on."

"And then?"

"Well, then, since the document is genuine, since I have, with my own
eyes, seen the marks of the red seals, since Marie Antoinette herself
assures me, by these few words in her hand, that the whole story of the
pamphlet, as printed by M. Massiban, is correct, because a problem of
the Hollow Needle really exists, I am now certain to succeed."

"But how? Whether genuine or not, the document is of no use to you if
you do not manage to decipher it, because Louis XVI. destroyed the book
that gave the explanation."

"Yes, but the other copy, which King Louis XVI.'s captain of the guards
snatched from the flames, was not destroyed."

"How do you know?"

"Prove the contrary."

After uttering this defiance, Beautrelet was silent for a time and
then, slowly, with his eyes closed, as though trying to fix and sum up
his thoughts, he said:

"Possessing the secret, the captain of the guards begins by revealing
it bit by bit in the journal found by his descendant. Then comes
silence. The answer to the riddle is withheld. Why? Because the
temptation to make use of the secret creeps over him little by little
and he gives way to it. A proof? His murder. A further proof? The
magnificent jewel found upon him, which he must undoubtedly have taken
from some royal treasure the hiding-place of which, unknown to all,
would just constitute the mystery of the Hollow Needle. Lupin conveyed
as much to me; Lupin was not lying."

"Then what conclusion do you draw, Beautrelet?"

"I draw this conclusion, my friends, that it be a good thing to
advertise this story as much as possible, so that people may know,
through all the papers, that we are looking for a book entitled The
Treatise of the Needle. It may be fished out from the back shelves of
some provincial library."

The paragraph was drawn up forthwith; and Beautrelet set to work at
once, without even waiting for it to produce a result. A first scent
suggested itself: the murder was committed near Gaillon. He went there
that sam