"Joe! I wish you could talk Indian! I could kiss you for this trick!"
Brown's voice said anxiously: "I'm going to let that manned rocket have a couple more shots."
"Let us get by first," said Joe. "Then maybe you can use them on the bombs coming up."
He could see the trails of war-rockets on the way out from Earth. They were infinitesimal threads of vapor. They were the thinnest possible filaments of gossamer white. But they enlarged as they rose. They were climbing at better than two miles per second, now, and still increasing their speed.
But the arena in which this conflict took place was so vast that everything seemed to take place in slow motion. There was time to reason out not only the method of attack from Earth, but the excuse for it. If the Platform vanished from space, no matter from what cause, its enemies would announce vociferously that it had been destroyed by its own atomic bombs, exploding spontaneously. Even in the face of proof of murder, enemy nations would stridently insist that bombs intended for the enslavement of humanity—in the Platform—had providentially detonated and removed that instrument of war-mongering scoundrelly imperialists from the skies. There might be somebody, somewhere, who would believe it.
Joe and the Chief were steadied now nearly on a line to intercept the rising manned rocket. They had already fired their missiles, which trailed them. They went into battle, not prepared to shoot, but with their ammunition expended. For which there was excellent reason.
Something came foaming toward them from the nearby man-carrying rocket. It seemed like a side-spout from the column of vapor rising from Earth. Actually it was a guided missile.
"Now we dodge," said Joe cheerfully. "Remember the trick of this maneuvering business!"
It was simple. Speeding toward the rising assassin, and with his missiles rushing toward them, the relative speeds of the wagons and the missiles were added together. If the space wagons dodged, the missile operator had less time to swing his guided rockets to match the change of target course. And besides, the attacker hadn't made a single turn in space. Not yet. He might know that a rocket doesn't go where it's pointed, as a matter of theory. He might even know intellectually that the final speed and course of a rocket is the sum of all its previous speeds and courses. But he hadn't used the knowledge Joe and the Chief had.
Something rushed at them. They went into evasive action. And they didn't merely turn the noses of their space wagons. They flung them about end-for-end, and blasted. They used wholly different accelerations at odd angles. Joe shot away from Earth on steering rocket thrust, and touched off a four-three while he faced toward Earth's north pole, and halfway along that four-second rush he flipped his craft in a somersault and the result was nearly a right-angled turn. When the four-three burned out he set off a twelve-two, and halfway through its burning fired a three-two with it, so that at the beginning he had two gravities acceleration, then four gravities for three seconds, and then two again.