“You know; I went immediately to the person who had charge of the sale.”

“Very well! and afterwards?”

“I examined the catalogue; and as, among the jewels mentioned, I could find none that answered the description of these diamonds, I knew that the clue was quite lost.”

“There is precisely where you are mistaken!” exclaimed old Tirauclair, exultantly.  “If such valuable jewels are not mentioned in the catalogue of the sale, the Baroness de Watchau could not have possessed them at the time of her death.  And if she no longer possessed them she must have given them away or sold them.  And who could she have sold them to?  To one of her lady friends, very probably.  For this reason, had I been in your place, I should have found out the names of her intimate friends; this would have been a very easy task; and then, I should have tried to win the favor of all the lady’s-maids in the service of these friends.  This would have only been a pastime for a good-looking young fellow like you.  Then, I should have shown this earring to each maid in succession until I found one who said:  ‘That diamond belongs to my mistress,’ or one who was seized with a nervous trembling.”

“And to think that this idea did not once occur to me!” ejaculated Lecoq.

“Wait, wait, I am coming to the second mistake you made,” retorted the oracle.  “What did you do when you obtained possession of the trunk which May pretended was his?  Why you played directly into this cunning adversary’s hand.  How could you fail to see that this trunk was only an accessory article; a bit of ‘property’ got ready in ‘mounting’ the ‘comedy’?  You should have known that it could only have been deposited with Madame Milner by the accomplice, and that all its contents must have been purchased for the occasion.”

“I knew this, of course; but even under these circumstances, what could I do?”

“What could you do, my boy?  Well, I am only a poor old man, but I should have interviewed every clothier in Paris; and at last some one would have exclaimed:  ’Those articles!  Why, I sold them to an individual like this or that—­who purchased them for one of his friends whose measure he brought with him.’”

Angry with himself, Lecoq struck his clenched hand violently upon the table beside him.  “Sacrebleu!” he exclaimed, “that method was infallible, and so simple too!  Ah!  I shall never forgive myself for my stupidity as long as I live!”

“Gently, gently!” interrupted old Tirauclair.  “You are going too far, my dear boy.  Stupidity is not the proper word at all; you should say carelessness, thoughtlessness.  You are young—­what else could one expect?  What is far less inexcusable is the manner in which you conducted the chase, after the prisoner was allowed to escape.”

“Alas!” murmured the young man, now completely discouraged; “did I blunder in that?”

“Terribly, my son; and here is where I really blame you.  What diabolical influence induced you to follow May, step by step, like a common policeman?”