* * * * * Tommy was tense and alert as Von Holtz opened the door of the barnlike laboratory. He waved the lean young man on ahead. "After you," he said curtly. He felt almost a shiver as he entered. But the interior of the laboratory displayed no gruesome scene. It was a huge, high-ceilinged room with a concrete floor. A monster dynamo was over in one corner, coupled to a matter-of-fact four-cylinder crude-oil engine, to which was also coupled by a clutch an inexplicable windlass-drum with several hundred feet of chain wrapped around it. There were ammeters and voltmeters on a control panel, and one of the most delicate of dynamometers on its own stand, and there were work benches and a motor-driven lathe and a very complete equipment for the working of metals. And there was an electric furnace, with splashes of solidified metal on the floor beside it, and there was a miniature casting-floor, and at the farther end of the monster room there was a gigantic solenoid which evidently had once swung upon gymbals and as evidently now was broken, because it lay toppled askew upon its supports. The only totally unidentifiable piece of apparatus in the place was one queer contrivance at one side. It looked partly like a machine-gun, because of a long brass barrel projecting from it. But the brass tube came out of a bulging casing of cast aluminum and there was no opening through which shells could be fed. * * * * * Von Holz moved to that contrivance, removed a cap from the end of the brass tube, looked carefully into the opening, and waved stiffly for Tommy to look in. Again Tommy was suspicious; watched until Von Holtz was some distance away. But the instant he put his eye to the end of the brass tube he forgot all caution, all suspicion, all his doubts. He forgot everything in his amazement. There was a lens in the end of the brass tube. It was, in fact, nothing more or less than a telescope, apparently looking at something in a closed box. But Tommy was not able to believe that he looked at an illuminated miniature for even the fraction of a second. He looked into the telescope, and he was seeing out-of-doors. Through the aluminum casting that enclosed the end of the tube. Through the thick brick walls of the laboratory. He was gazing upon a landscape such as should not--such as could not--exist upon the earth. There were monstrous, feathery tree-ferns waving languid fronds in a breeze that came from beyond them. The telescope seemed to be pointing at a gentle slope, and those tree-ferns cut off a farther view, but there was an impenetrable tangle of breast-high foliage between the instrument and that slope, and halfway up the incline there rested a huge steel globe. Tommy's eyes fixed themselves upon the globe. It was man-made, of course. He could see where it had been bolted together. There were glassed-in windows in its sides, and there was a door.