She, too, was looking out toward the dancing couples. He took her impulsively in his arms and for a moment she clung to him. "You can come back to me later on this evening when you and father are through," she whispered. He wanted to crush her to him, wanted to whisper "If I do come back, if there is a 'later on this evening' for me." But he only pressed her fingers lightly. "Save me a dance," he said, and hurried away down the narrow path to Professor Ploving's shop. * * * * * The things that Professor Ploving and his young assistant did there in the shop were known only to themselves; even those in the immediate family had long ago learned to ask no questions and, above all, never to "snoop." Ploving was no more immune than others to longings for fame, but years of observing with his keen, analytical mind the affairs of men both in and out of laboratories, had taught him caution. A professor of the august University of London, even a professor of independent wealth and impeccable family, could hardly dare lay himself open to ridicule. Had he been seeking to release atomic energy he could have spoken glibly and weightily of corpuscular radiations and electrodes and atom-smashing and even the news-reporters would have managed to splash him upon the Sunday feature pages as a brainy and adventurous fellow and a chap to know. But let him once point to his much discussed mathematical equations on his theory of the time-curve and suggest that he intended to utilize his theory in a most practical way and the world, he knew, would shout "time machine" and "crack-pot." For time machines, in 1931, were things to be left to H. G. Wells and to the rising crop of talented and imaginative English and American fantasy writers. It was no doings for a man of action and, above all, for a man of science. Steve Darville closed the workshop door behind him, muting the tom-tom rhythms of the music from the terrace lawn. The Ploving Tube stood with its small door, not unlike the door of a Channel transport plane, swinging open. The professor was beside it, wiping his glasses on a linen kerchief, trying to hide the nervousness that made the knotty blue veins of his hands jerk spasmodically. He had thrown open the small window at the south wall and through it Steve caught a glimpse of the rooftops of the newly-built Ploving Laboratories which lay just under the hill, almost beside the Channel. The laboratories that were to mean so much--or nothing. Intricate calculations, founded upon his own theories of the "time-curve," had been utilized by Professor Ploving in creation of the Ploving Tube, a cylinder most undramatic in appearance. But the heart of the tube was the tiny Ploving Button, a small incased mechanism no more than an inch in thickness and a couple of inches in diameter. If the tube were to be a success, it must depend upon that one tiny button.