"So," he mused, as he walked along, "the Warburton servant has had her orders. That was precisely the information I wanted. These women were not beggars, but messengers, and they brought no message of the ordinary kind." Suddenly he uttered a sharp ejaculation, and quickened his pace. "That old woman--why, she answers perfectly the description given of Mother Francoise! And if it _is_ Mother Francoise, she has undoubtedly brought a message to Alan Warburton. If it is that old woman, I will soon know it, for I shall not take my two eyes off her until I have tracked her home." CHAPTER XXV. WHO KILLED JOSEF SIEBEL. While Van Vernet was following after the two women, the carriage with the restless horses moved slowly past the Warburton dwelling. An observer might have noted that the face of the crape-draped occupant was pressed close against the oval window, in the rear of the vehicle, watching the direction taken by Van Vernet. Then, suddenly, this individual leaned forward and said to the driver: "Around the corner, Jim, and turn." The order was promptly obeyed. "Now back, Jim," said this fickle-minded person. Then as the carriage again rounded the corner: "You see that fellow in policeman's uniform, Jim?" "Yes, sir." "Follow him." Slowly the carriage moved along, picking its way across crowded thoroughfares, for many blocks, the occupant keeping a close watch upon the movements of Van Vernet, this time through the window in front. Finally, leaning back in the carriage with a muttered, "That settles it; he's going to track them home," he again addressed the driver: "Turn back, Jim." "All right, sir." "Drive to Warburton Place, side entrance." Leslie Warburton, her vigil being over, was alone in her room, pacing restlessly up and down, a look of dire foreboding on her face, and in her hand a crumpled note. At the sound of an opening door she turned to confront her maid, who proffered her a card. Leslie took it mechanically and then started as she read thereon: MADAM STANHOPE, Modeste. And written in the corner of the card, the underlined word, _Imperative_. There was a look of relief upon the face she turned to the servant. "Where is the--lady?" "In the little drawing-room, madam." Holding the card in her hand, Leslie hastened to the little drawing-room. A tall, veiled woman advanced to meet her; it was the occupant of the carriage. Leslie came close to this sombre-robed figure and said, almost in a whisper: "Mr. Stanhope?" "It is I, Mrs. Warburton. Need I say that only the most urgent necessity could have brought me here at such a time?" "It is the right time, sir." She held up before him the crumpled note. "It is from _them_?" he asked. Leslie nodded. "It contains the secret of their present whereabouts, and bids you come to them?" "Yes." "You will not go?" "How can I, now?"--her voice almost a wail--"and yet--"