With one hand, she struck the window feebly as with the other she raised what appeared to be a piece of paper before the eyes of the astonished pair. Then, laying the paper against the glass, she drew back into the darkness and disappeared. "Remain where you are, Edna!" cried Frank, springing toward the door. "In a moment I will return." He was in the street in an instant. Too late! The woman was nowhere to be seen. But there upon the window-sill, leaning against the glass, still rested a folded parchment, affording the most positive evidence of her presence before the house. Search was useless. Whoever the strange creature might be--if a being of this world indeed--she had but to turn the corner of Bleecker street to lose herself in the crowd. With his mind filled with a thousand doubts and fears, Frank seized the parchment and returned to the room. Without speaking a word he strode toward the table, and spread it out beneath the lighted lamp. His eyes had scarce rested upon it than he uttered an exclamation of joyful surprise. And no wonder. It was the description of the treasure hidden by old Jeremiah Mansfield, his grandfather, which lay before him. As though a gift from Heaven, it had been restored to him. He had watched and waited. The missing parchment had been placed in his hands. CHAPTER XXII. AN UNTIMELY OCCURRENCE--CALEB HOOK DISCOVERED. "Hist--hist, Jerry Buck!" whispered Detective Hook as he slipped through the door opened by the newsboy. "You are a smart lad--a bright lad--to track those fellows as you have. I watched you do it, but, having got them into close quarters, we must put our heads together and find out what's going on in the room below." Both Jerry Buck and the woman drew back in startled surprise. The appearance of the detective thus unexpectedly, was, to judge from the countenances of both, anything but welcome to them. For the moment even the ready wit of the Bat seemed to desert him, and he glanced from the face of the woman, who stood motionless behind the stove with her foot covering the hole in the floor, to that of Caleb Hook with an appearance of deep perplexity, not unmingled with fear. "I don't know what you mean, mister. I----" "Stop, Jerry. This is no time to lie. You know me well enough. Have you forgotten the morning at the Catherine Market--my visit to the Bats in the Wall?" "Well, s'pose I hain't? What's that got to do with it? This here's a private room. What call have you got to run your nose in here?" "One moment, Jerry," said the detective, coolly pushing the boy aside and advancing into the room. "Madam, your most obedient," he continued, bowing respectfully to the woman. "My name is Hook. I am a police detective and the best friend Frank Mansfield has got. May I trouble you to tell me who and what you are?" The woman trembled before him. A wild, hunted look overshadowed her face; her eyes wandered restlessly about the room.