"The picture," he muttered low. Twisting an arm about a steel beam, with no thought of the dizzy depths below, with fingers that trembled ever so slightly, he adjusted an electric light bulb, half filled with a sort of tinfoil, to his flashlight. Then adjusting his small camera, he shifted his position, held camera and flashlight high, then pressed a button. The result was most astonishing. A bright flash was to be expected. The tinfoil filled bulb was such as newspaper photographers use for taking flashlight pictures. Yes, that first bright flash was to be expected. The second, following closely upon the first and accompanied by a sharp report, had not been anticipated. A bullet burned Spider's ear. With a cry of consternation, he released his grip, dropped a short way toward the black depths below, struck a steel beam, threw out his hands, clutched something cold and substantial, then hung there between heaven and earth. The first indication that all had not gone well came to Johnny when some object falling from the sky crashed upon a square of wind-blown pavement not twenty feet from where he stood. Springing forward, he cast the light of his electric torch upon some black fragments scattered over the spot where the thing had struck. "The--the camera!" he whispered. "Spider's camera. There'll be no picture. But Spider. What of him?" The wind that whistled about the foot of the Sky Ride tower brought him no answer. He had been watching the top of that tower for a full five minutes when some object, gliding along a cluster of four cables closely set together and running at a broad angle from the top of the tower to the ground, suddenly caught his attention. "Can that be a man?" he asked himself, staring with all his eyes as the thing moved downward. "If it's a man, is it Spider or the Whisperer?" he asked himself a moment later. Determined to know, he went racing away toward the end of the cable, some three blocks away. He arrived just in time to see the slider drop to earth. It was Spider. "Quite a sky-slider, I am!" he chuckled. "Well done!" exclaimed Johnny. "Did you see him?" "Not very clearly. He's a man, all right. And he's a tiger. Nearly got me. Never again!" Spider led the way off the grounds. And so for the time the mystery of the Whisperer remained unsolved. Only this was known with a fair degree of certainty: his place of retreat was one high tower of the Sky Ride. CHAPTER XXI CHRISTMAS EVE The dawn of the day before Christmas arrived and with it, in Grace Krowl's tiny parlor, came the hoarse whisper of the mysterious one: "Tonight," it insisted, "you will not fail me. It is for the good of all. You owe us more than you know. It is we who beautified your living quarters. Your coming disturbed our plans. But if you do this thing for us you shall be forgiven." "Plans." It was her turn to whisper. "What plans?" She wanted to know.