Was M. Lecoq really in anger? Fanferlot, who knew him well, doubted it a little; but with this devil of a man one never quite knew how to take him.
"If you were only clever," he continued, "but no! You wish to be a master, and you are not even a good workman."
"You are right, master," said Fanferlot piteously, who could deny no longer. "But how could I work upon a business like this, when there was no trace, no mark, no sign, no conviction,—nothing, nothing?"
M. Lecoq raised his shoulders.
"Poor boy!" he said. "Know, then, that the day when you were summoned with the commissary to verify the robbery, you had—I will not say certainly but very probably—between your two large and stupid hands the means of knowing which key, the banker's or the cashier's, had been used in committing the theft."
"What an idea!"
"You want proof? Very well. Do you remember that mark which you observed on the side of the copper? It struck you, for you did not repress an exclamation when you saw it. You examined it carefully with a glass; and you were convinced that it was quite fresh, and therefore made recently. You said, and with reason, that this mark dated from the moment of the theft. But with what had it been made? With a key, evidently. That being the case, you should have demanded the keys of the banker and the cashier, and examined them attentively. One of these would have shown some atoms of the green paint with which a strong-box is usually coated."
Fanferlot listened with open mouth to this explanation. At the last words, he slapped his forehead violently, and cried—of himself—"Imbecile!"
"You are right," replied M. Lecoq—"imbecile. What! With such a guide before your eyes, you neglected it and drew no conclusion! This is the one clue to the affair. If I find the guilty one, it will be by means of this mark, and I will find him; I am determined to do it."
When away from Lecoq, Fanferlot, nicknamed the Squirrel, often slandered and defied him; but in his presence he yielded to the magnetic influence which this extraordinary man exercised upon all who came near him.