Mr. Ricardo was not persuaded because he would not be. "I have some experience in these matters," he said loftily to Hanaud. "I am sure that we shall lay our hands upon the criminals. We have never failed." Hanaud grinned from ear to ear. The only experience which Mr. Ricardo had ever had was gained on the shores of Geneva and at Aix under Hanaud's tuition. But Hanaud did not argue, and there the matter rested. The days flew by. It was London's play-time. The green and gold of early summer deepened and darkened; wondrous warm nights under England's pale blue sky, when the streets rang with the joyous feet of youth, led in clear dawns and lovely glowing days. Hanaud made acquaintance with the wooded reaches of the Thames; Joan Carew sang "Louise" at Covent Garden with notable success; and the affair of the Semiramis Hotel, in the minds of the few who remembered it, was already added to the long list of unfathomed mysteries. But towards the end of May there occurred a startling development. Joan Carew wrote to Mr. Ricardo that she would call upon him in the afternoon, and she begged him to secure the presence of Hanaud. She came as the clock struck; she was pale and agitated; and in the room where Calladine had first told the story of her visit she told another story which, to Mr. Ricardo's thinking, was yet more strange and--yes--yet more suspicious. "It has been going on for some time," she began. "I thought of coming to you at once. Then I wondered whether, if I waited--oh, you'll never believe me!" "Let us hear!" said Hanaud patiently. "I began to dream of that room, the two men disguised and masked, the still figure in the bed. Night after night! I was terrified to go to sleep. I felt the hand upon my mouth. I used to catch myself falling asleep, and walk about the room with all the lights up to keep myself awake." "But you couldn't," said Hanaud with a smile. "Only the old can do that." "No, I couldn't," she admitted; "and--oh, my nights were horrible until"--she paused and looked at her companions doubtfully--"until one night the mask slipped." "What--?" cried Hanaud, and a note of sternness rang suddenly in his voice. "What are you saying?" With a desperate rush of words, and the colour staining her forehead and cheeks, Joan Carew continued: "It is true. The mask slipped on the face of one of the men--of the man who held me. Only a little way; it just left his forehead visible--no more." "Well?" asked Hanaud, and Mr. Ricardo leaned forward, swaying between the austerity of criticism and the desire to believe so thrilling a revelation. "I waked up," the girl continued, "in the darkness, and for a moment the whole scene remained vividly with me--for just long enough for me to fix clearly in my mind the figure of the apache with the white forehead showing above the mask." "When was that?" asked Ricardo. "A fortnight ago." "Why didn't you come with your story then?"