"That's the best I can describe this force, Masters. I might call it heat-bolts, but it's probably partly electric and partly heat, not entirely either. You see, Masters, heat is energy, just like electricity and light. The energy these spheres shoot out is a mixture of energies. We can imagine a spark of electricity shooting out and striking a man like a bolt of lightning, but it's hard to visualize heat behaving that way." "Say, mister," the sentry interrupted, "my arms are getting tired." "Okay, buddy," Masters replied. "If I let you put your arms down, will you behave like a nice little boy?" "I'll be a perfect angel," the sentry said, lowering his arms. "You'll be an angel if you aren't, too," Masters added. "What's your name, soldier?" Taylor asked the sentry. "Private Pember, sir. Company A, 110th infantry--" "All right, Private Pember, you can carry this fellow." Taylor shifted the faintly stirring Norden to the shoulders of the soldier. "If it will make you feel any easier, Pember," the captain went on, "I can assure you that exigencies demanded your removal from your post. Your life was in danger and you could do no good by remaining there. In fact, there was nothing left to guard. You can do more good for your country by coming with us." "Yes, sir," Pember said. "I guess you are right, captain." "You're a good soldier, Pember," Taylor went on. "A situation like this is unique. It demands use of individual initiative, rather than blind obedience to orders. Do you understand?" "Yes, sir," Pember said, adjusting the burden on his shoulder. * * * * * They reached the car. A dozen of the orange-red globes now floated above the plant. They were circling slowly, in widening arcs, toward the limits of the factory grounds. "Searching for human beings," Taylor decided, watching them. Orkins clutched Taylor's coat tails. "They're coming out!" he cried. "There's hell to pay." Taylor took Orkins' arm and forced him down on the running board of the car, where Norden already was coming out of his daze. "Keep quiet!" Taylor ordered. "They'll discover us." "They'll find us anyway!" Orkins said, frantic with fear. He groaned loudly. "Okay. He asked for it," Masters said. There was a splatting sound as Masters' fist landed. Masters made a face over a distasteful duty done and turned to Pember: "Put them both in the car." He indicated Norden. "Here's handcuffs. Lock them together." Taylor and Masters watched the circling spheres. Suddenly one darted down. From its pulsating body shot a flash of flame. A human scream rent the air. "It's the darnedest thing I ever saw," Masters said with a shudder. "Those fireballs squirt heat-electricity out at a guy and roast him!" "Yes," Taylor said with a nod, "and that isn't all. Those spheres act as though they were alive. When that one went out above the opening of the tunnel, I thought I saw a pair of eyes." Masters studied the assertion, then spoke: