"Now here is the point of greatest interest." Again the Talsonian fell to work on his dials, watching the ball of fire. It seemed far more brilliant in the air now. It moved, and headed toward a great slab of steel off to one side of the laboratory. It shifted about until it was directly over the center of the great slab. The slab rested on a scale of some sort, and as the ball of fire touched it, the scale showed a sudden increase in load. The ball sank into the slab of steel, and the scale showed a steady, enormous load. Evidently the little ball was pressing its way through as though it were a solid body. In a moment it was through the steel slab, and out on the other side. "It will pass through any body with equal ease. It seems to answer only these controls, and these it answers perfectly, and without difficulty. "One other thing we can do with it. I can increase its rate of energy discharge." The Talsonian turned a fourth dial, well off to one side, and the brilliance of the spot increased enormously. The heat was unbearable. Almost at once he shut it off. "That is the principle we use in making it a weapon. Watch the actual operation." The ball of fire shot toward an open window, out the window, and vanished in the sky above. The Talsonian stopped the rotation of the dials. "It is motionless now, but scarcely visible. I will now release all the energy." He twirled the fourth dial, and instantly there was a flash of light, and a moment later a terrific concussion. "It is gone." He left the controls, and went over to his apparatus. He set a heavy silver bladed switch, and placed a new tube in the apparatus. A second switch arced a bit as he drove it home. "Your generator is recharging the accumulators." Stel Felso Theu took the backplate of the control cabinet off, and the terrestrians looked at the control with interest. "Got it, Morey?" asked Arcot after a time. "Think so. Want to try making it up? We can do so out of spare junk about the ship, I think. We won't need the tube if what I believe of it is true." Arcot turned to the Talsonian. "We wish you to accompany us to the ship. We have apparatus there which we wish to set up." Back to the ship they went. There Arcot, Morey and Wade worked rapidly. It was about three-quarters of an hour later when Arcot and his friends called the others to the laboratory. They had a maze of apparatus on the power bench, and the shining relux conductors ran all over the ship apparently. One huge bar ran into the power room itself, and plugged into the huge power-coil power supply. They were still working at it, but looked up as the others entered. "Guess it will work," said Arcot with a grin.