“Some one has been here in our absence.”

“Impossible!”

It was not impossible—it was true. When Gevrol had torn the apron off Widow Chupin’s head he had thrown it upon the steps of the stairs; neither of the police agents had since touched it. And yet the pockets of this apron were now turned inside out; this was a proof, this was evidence. At this discovery Lecoq was overcome with consternation, and the contraction of his features revealed the struggle going on in his mind. “Who could have been here?” he murmured. “Robbers? That is improbable.”

Then, after a long silence which his companion took good care not to interrupt, he added: “The person who came here, who dared to penetrate into this abode and face the corpses of these murdered men—this person could have been none other than the accomplice. But it is not enough to suspect this, it is necessary to know it. I must—I will know it!”

They searched for a long time, and it was not until after an hour of earnest work that, in front of the door forced open by the police, they discovered in the mud, just inside the marks made by Gevrol’s tread, a footprint that bore a close resemblance to those left by the man who had entered the garden. They compared the impressions and recognized the same designs formed by the nails upon the sole of the boot.

“It must have been the accomplice!” exclaimed Lecoq. “He watched us, he saw us go away, and then he entered. But why? What pressing, irresistible necessity made him decide to brave such imminent danger?” He seized his companion’s hand, nearly crushing it in his excitement: “Ah! I know why!” continued he, violently. “I understand only too well. Some article that would have served to throw light on this horrible affair had been left or forgotten, or lost here, and to obtain it, to find it, he decided to run this terrible risk. And to think that it was my fault, my fault alone, that this convincing proof escaped us! And I thought myself so shrewd! What a lesson! The door should have been locked; any fool would have thought of it—” Here he checked himself, and remained with open mouth and distended eyes, pointing with his finger to one of the corners of the room.

“What is the matter?” asked his frightened companion.

Lecoq made no reply, but slowly, and with the stiff movements of a somnambulist, he approached the spot to which he had pointed, stooped, picked up something, and said: “My folly is not deserving of such luck.”

The object he had found was an earring composed of a single large diamond. The setting was of marvelous workmanship. “This diamond,” declared Lecoq, after a moment’s examination, “must be worth at least five or six thousand francs.”

“Are you in earnest?”