The room in which they stood was obviously a laboratory. Bulky gas engines and a generator squatted at one end; tables held racks of tools and loops of insulated wiring and jars of various chemicals. One long table stretched the whole length of the room, placed flush against the left wall, whose rough planking was broken by a lone window. There were racks of test tubes on this table, and tools, carelessly scattered by men intent on their work. Still another table was devoted to several cages, containing the usual martyrs of experimental science: guinea pigs and rabbits, rats and white mice. Beside these was a large box, screen topped, in which, in separate partitions, were a variety of insects: beetles and flies and spiders and tarantulas. But the thing that dominated the laboratory was the machine on the long table against the wall. Its chamber, the most striking feature, was a cube of roughly six feet, built of dull material resembling bakelite. Wires trailed through it from the glittering plate, which was the chamber's floor, and a curved spray-shaped projector overhead, to an intricately constructed apparatus studded with vacuum tubes. A small switchboard stood beside the chamber, and from it thick cables led to the generator in the rear of the room. "Let us return her to normal," Hagendorff rumbled after a moment or two devoted to prodding and examining the diminutive cat. "Then for the final experiment." One whole wall of the cubical chamber was a hinged door, with a tier of several peep-holes. Garth Howard swung the door open, placed the tiny, struggling cat inside and quickly closed it again. "Right," he said briefly, and pressed his eyes to the bottom peep-hole. * * * * * A switch was pulled over, and the dynamo's drone pulsed through the room. Hagendorff's fingers rested on a large lever that jutted from the switchboard. Slowly, he pulled it to one side. The imprisoned cat, small as a rat, had been nervously whipping its tail from side to side and meowing plaintively; but, as the lever swung over, there came a change. The vacuum tubes behind the switchboard glowed green; a bright white ray poured from the spray in the chamber, making the metal plate below a shimmering, almost molten thing. The animal's legs suddenly braced on it; its narrowed eyes widened, glazing weirdly, while the tail became a stiff, bristling ramrod. And, as a balloon swells from a strong breath, the cat's body increased in size. It grew not in spurts, but with a smooth, flowing rhythm: grew as easily as a flower unfolding beneath the sun. In only a few seconds its original size was attained. Howard raised his hand; the lever shot back and the white beam faded into nothingness. A full sized and very angry cat tore around the inside of the chamber. "Normal?" Hagendorff questioned. The other nodded and prepared to open the door. "Wait! She always was a little undersized; I give her a few inches more as a reward."