Then they heard explosions far ahead. Flames lighted the sky. "Our men in action!" said Sergeant Walpole hungrily. He flogged his mount mercilessly. Then the sky became bright in the distance. The horses, going down the crushed-smooth trail of the treads, gained upon the din. Then they saw the cause of it, miles distant. A train was burning luridly. Its forepart was wreckage, pure and simple. The rest was going up in flames and detonations. Munitions, of course. The Wabbly was off at one side, flame-lit and monstrous, sliding smoothly out of sight. * * * * * "Ten miles of railroad," said the 'copter pilot calmly, "mashed out of existence. That's going to scare our people into fits. They can drop eggs till the cows come home, and every egg'll smash up a hundred yards of right-of-way, and we can build it back up again in four hours with mobile track-layers. But ten miles to be regraded and laid is different. Half of America will be imagining all our railroads smashed and starvation ahead." A piercing light fell upon them. "Shut it off!" roared Sergeant Walpole. "D'y'want to get us killed?" He and the 'copter pilot swerved. There was a car there, a huge two-wheeled car, whose gyroscopes hummed softly while its driver tried to extract it from something it was tangled in. "I commandeer this car," said the 'copter pilot. "Military necessity. We have to trail that Wabbly." Someone grunted. Lights flashed on within. The 'copter pilot and Sergeant Walpole stiffened to attention. The stars of a major-general shone on the collar of the stout man within. "Beg pardon, sir," said the pilot, and was still. "Umph," said the major-general. "There seem to be just four of us alive, who've seen the thing clearly. I hit on it by accident, I'll admit. What do you know about it?" "It come on a tramp-steamer--" began Sergeant Walpole. "Hm. You're Sergeant Walpole. Mentioned in dispatches to-morrow, Sergeant. You, sir?" "Its weapon against our planes, sir," said the 'copter man precisely, "is a radio beam carrying several thousand horsepower of energy. When it hits iron, sir, the energy is absorbed and the iron heats up and blows up the ship. The Wabbly's working with a bomber well aloft, sir, which spots planes from below by picking up their spark-plug flashes in a directional loop. The bomber aloft, sir, drops eggs when the Wabbly's attacked. Sergeant Walpole reports several planes disabled by their fabric being blown off their wings." * * * * * "I know," said the major-general. "Dammit, the front takes every ship that's fit to go aloft. We have only wrecks back here. You're sure about that spark-plug affair?" "Yes, sir," said the 'copter pilot. "My ship crashed, sir. I started the motors again, trying to take off. Eggs began to drop about me instantly."