What had happened was, she now explained, that after visiting several shops and making a number of purchases, she had stepped into Central Park at the Plaza for a breath of fresh air before lunching at the Sherry-Netherlands, where she planned to meet some friends. But before advancing a hundred yards along the secluded path, she had been seized by invisible hands--had felt something strapped to her wrist, before anyone came in sight--and then, invisible too, had been lifted up, whirled away into a vast, humming vibration that sounded through the air. Once on the disc, it had swept off into space at incredible speed, pausing only when some hundreds of miles above the earth and invisible from below without mechanical aid. When its vibration finally ceased that amazing city had leapt before her eyes. Then, her own visibility restored, she had been led into the presence of that mighty little monarch, Cor, who explained that she had been seized as a hostage and would be held as an ace in the hole, pending conquest of her country. Since when she had been a prisoner aboard the disc. * * * * * Learning of Kendrick's capture, from gossip among the women, she had taken the first opportunity of coming to him, in the hope that between them they might devise some means of escape. Indeed, that was his own fondest hope--their imperative need, if the people of America and of the earth were to be saved from this appalling menace. But what basis was there for such a fantastic hope? Just one, that he could see. "That thing on your wrist," he said, voicing it. "I'm surprised they let you wear one of those." "They don't," she smiled. "I stole it!--from one of the maids in my apartment. It was the only way I could get here without being seen. I felt I must see you at once. We've got to do something, soon, or it'll be too late. I felt that, as a scientist, you might have some idea how we could get off." "How do the people themselves get off?" he asked. "That escalator ray--do you know how they use it?" "No, I've never been able to find out. They don't let me go near that part of the city." Kendrick reflected a moment. "Let's have a look at that invisibility affair," he said. She removed it from her wrist, handed it to him. Somewhat in awe, he examined it. * * * * * The mechanism portion, which was linked in a strap of elastic metal, resembled only superficially a watch, he now saw. Rather it had the appearance of some delicate electric switch. Rectangular in shape, it was divided into two halves by a band of white crystal. In each of these halves were two little buttons of the same material, those on one side round, on the other square. "Which buttons control the invisibility?" he asked. "The square ones," she replied. "One's pushed in now, you see. If you should push the other, the first would come out--and you'd pass out of the picture, so to speak."