Rouletabille went back to the door and carefully examined the lock and the bolt, satisfying himself that the door had certainly been burst open from the outside, and, further, that the key had been found in the lock on the inside of the chamber. He finally satisfied himself that with the key in the lock, the door could not possibly be opened from without with another key. Having made sure of all these details, he let fall these words: “That’s better!”—Then sitting down on the ground, he hastily took off his boots and, in his socks, went into the room. The first thing he did was to examine minutely the overturned furniture. We watched him in silence. “Young fellow, you are giving yourself a great deal of trouble,” said Daddy Jacques ironically. Rouletabille raised his head and said:— “You have spoken the simple truth, Daddy Jacques; your mistress did not have her hair in bands that evening. I was a donkey to have believed she did.” Then, with the suppleness of a serpent, he slipped under the bed. Presently we heard him ask:— “At what time, Monsieur Jacques, did Monsieur and Mademoiselle Stangerson arrive at the laboratory?” “At six o’clock.” The voice of Rouletabille continued: “Yes,—he’s been under here,—that’s certain; in fact, there was no where else where he could have hidden himself. Here, too, are the marks of his hobnails. When you entered—all four of you—did you look under the bed?” “At once,—we drew it right out of its place—” “And between the mattresses?” “There was only one on the bed, and on that Mademoiselle was placed; and Monsieur Stangerson and the concierge immediately carried it into the laboratory. Under the mattress there was nothing but the metal netting, which could not conceal anything or anybody. Remember, monsieur, that there were four of us and we couldn’t fail to see everything—the chamber is so small and scantily furnished, and all was locked behind in the pavilion.” I ventured on a hypothesis:— “Perhaps he got away with the mattress—in the mattress!—Anything is possible, in the face of such a mystery! In their distress of mind Monsieur Stangerson and the concierge may not have noticed they were bearing a double weight; especially if the concierge were an accomplice! I throw out this hypothesis for what it is worth, but it explains many things,—and particularly the fact that neither the laboratory nor the vestibule bear any traces of the footmarks found in the room. If, in carrying Mademoiselle on the mattress from the laboratory of the château, they rested for a moment, there might have been an opportunity for the man in it to escape.” “And then?” asked Rouletabille, deliberately laughing under the bed. I felt rather vexed and replied:— “I don’t know,—but anything appears possible”—