Wethermill took his letter-case from his pocket and a letter out of the case. He hesitated for a moment as he glanced over what was written. The four sheets were covered. He folded back the letter, so that only the two inner sheets were visible, and handed it to Hanaud. Hanaud compared it with the handwriting upon the card. "Look!" he said at length, and the three men gathered behind him. On the card the gummed fragments of paper revealed a sentence: "Je ne sais pas." "'I do not know,'" said Ricardo; "now this is very important." Beside the card Celia's letter to Wethermill was laid. "What do you think?" asked Hanaud. Besnard, the Commissaire of Police, bent over Hanaud's shoulder. "There are strong resemblances," he said guardedly. Ricardo was on the look-out for deep mysteries. Resemblances were not enough for him; they were inadequate to the artistic needs of the situation. "Both were written by the same hand," he said definitely; "only in the sentence written upon the card the handwriting is carefully disguised." "Ah!" said the Commissaire, bending forward again. "Here is an idea! Yes, yes, there are strong differences." Ricardo looked triumphant. "Yes, there are differences," said Hanaud. "Look how long the up stroke of the 'p' is, how it wavers! See how suddenly this 's' straggles off, as though some emotion made the hand shake. Yet this," and touching Wethermill's letter he smiled ruefully, "this is where the emotion should have affected the pen." He looked up at Wethermill's face and then said quietly: "You have given us no opinion, monsieur. Yet your opinion should be the most valuable of all. Were these two papers written by the same hand?" "I do not know," answered Wethermill. "And I, too," cried Hanaud, in a sudden exasperation, "je ne sais pas. I do not know. It may be her hand carelessly counterfeited. It may be her hand disguised. It may be simply that she wrote in a hurry with her gloves on." "It may have been written some time ago," said Mr. Ricardo, encouraged by his success to another suggestion. "No; that is the one thing it could not have been," said Hanaud. "Look round the room. Was there ever a room better tended? Find me a little pile of dust in any one corner if you can! It is all as clean as a plate. Every morning, except this one morning, this room has been swept and polished. The paper was written and torn up yesterday."