_Call who?_ the physicist wondered, and then forgot about it. He wanted desperately to dig into the sky car. He wanted to find out where the engineer had packed five tons of equipment. He wanted to see what made the wheels go around. No doubt the thing could be returned to its owners without calling in the police. The thing was probably recorded in the precisely kept engineering notebook of the physicist's alter ego. * * * * * The pilot model was not completely out of sight before Thomas had the power cowls off, and the whole model stripped of its servicing doors. They had done an excellent job of design; the sky car without its servicing panels was but a skeleton frame, with every line, every connection, and every control rod open for easy servicing. And it was then and there that the physicist understood what the engineer had been doing. Instead of the low-voltage high-current supply lines, with their attendant heavy busbars, thin pipes ran about the sky car. Seamless aluminum tubing carried the energizing current. Or, rather the space inside of the tubing carried it. At the generator end, a ten megawatt microwave generator supplied high power at ultra high frequency. At the terminus, rectifiers brought the ultra high frequency down to direct current for operation of the force-field generators. Thomas nodded. It was not the final tenth of one percent job. It was not direct current. The diagravitic force was not constant. It operated only seven tenths of the time, and was turned off and on fifteen or twenty million million times per second. Nothing short of high-definition test equipment would ever tell the difference, however. Gone were the massive electromagnetic deflection field coils. In their place was a set of seventy kilovolt electrostatic plates. Missing entirely were the variable-speed motor generators. In their place was a simple crystalline formation under permanent magnetic stress. "Artificial radio-activated crystals," muttered Thomas. "Good for a couple of years." But the feed lines. _The feed lines._ The current carrying ability of space itself--not the metallic conductor--did the trick. Using the ultra high frequency bands, the busbars had been replaced with cylindrical wave guides. The depth of penetration was measured in microns at those frequencies--and as long as the guides were properly designed, they offered little loss in power. The current went down the wave guides by virtue of the magnetic fields created throughout the guides--magnetic fields generated in the space inside of the tubular guides. The generator itself was one of the new crystal microwave generators and the rectifiers at the receiving end were of the same ilk. And the five tons of equipment had vanished in a puff of tubular guides, electrostatic plates, and intermittent operation.