This gave Vicky a start, and we heard the street door slam as we raced down the stairs. Here, too, we lost a second or two, for I stepped back to give Stone space just as he did the same for me, and when we had reached the foot of the stairs, leaped through the hall, wrenched open the door and dashed down the steps to the pavement, we saw the flying figure of Vicky Van round the Fifth Avenue corner, and turn South. After her we ran, as fast as mortal man can run, I verily believe, and when we reached the Avenue there was no one in sight! Stone stood stock-still, looking down the street. The Avenue was lighted, as usual, and we could see a block and more in both directions, but no sign of Vicky. Nor was there a pedestrian abroad, or a motor. The Avenue was absolutely uninhabited, as far as our eyes could reach. "Where'd she go?" I panted. "Into some house, or, maybe, hiding in an area. We must search them all, but very warily. She's a witch, a wonder-woman, but all the same, the earth didn't open and swallow her!" We searched every area way on the block. One of us would go in and explore while the other stood guard. The third house was the Schuyler residence, but Stone also searched thoroughly in its basement entrance. "All dark and locked up," he reported, as he came out from there. "And, of course, she wouldn't seek sanctuary there! But I've wondered if she isn't concealed in one of these nearby houses, as she has such ready access to her own home." But it was impossible. Every basement entrance was locked and bolted for the night and all the windows were dark. "She's given us the slip," said Stone, in deep chagrin. "But perhaps she crossed the street. Maybe she didn't run down this side very far. Let's go over." We crossed and looked over the stone wall of the park. Surely Vicky Van had not had time to scramble over that wall before we reached the corner. It had been not more than a few seconds after we saw her flying form turn down the Avenue, and she couldn't have crossed the street and scaled the wall in that time! Where was she? What had become of her? "Ring up the houses and inquire," I suggested. "You're justified in doing that." "No use," he responded. "If she was expected they won't give her away, and if she isn't there, they'd be pretty angry at our intrusion. I'll admit, Calhoun, I've never been so mystified in my life!" "Nor I!" I emphatically agreed. CHAPTER XVII THE GOLD-FRINGED GOWN After that night Fleming Stone became more desperately in earnest in his search for Vicky. It seemed as if the sight of her, the realization that she was a real woman and not a myth, had whetted his eagerness to discover her hiding place and bring her to book. He established himself in her house, and both he and Fibsy practically lived there, going out for their meals or picnicking in the basement room. This room became his headquarters, and a plain clothes man was on duty whenever Stone and Fibsy were both absent.