There were people running in the corridors, heading for their posts. Their faces were set, scared, uncomprehending. The _Quest III_ shuddered, again and again, under blows that must have had millions of horsepower behind them; but it plunged on toward Earth, its mighty engines still steadily braking its interstellar velocity. To a man, the ship's responsible officers were already on the bridge, most of them breathless. To a man they looked appeal at Captain Knof Llud. "Well?" he snapped. "What are they doing?" Gwar Den spoke. "There are thirteen of them out there now, sir, and they're all banging away at us." The captain stared into the black star-strewn depths of a vision screen where occasional blue points of light winked ominously, never twice from the same position. Knof Jr. flattened himself against the metal wall and watched silently. His young face was less anxious than his elders'; he had confidence in his father. "If they had anything heavier," surmised the captain, "they'd have unlimbered it by now. They're out to get us. But at this rate, they can't touch us as long as our power lasts--or until they bring up some bigger stuff." * * * * * The mild shocks went on--whether from projectiles or energy-charges, would be hard to find out and it didn't matter; whatever was hitting the _Quest III's_ shell was doing it at velocities where the distinction between matter and radiation practically ceases to exist. But that shell was tough. It was an extension of the gravitic drive field which transmitted the engines' power equally to every atom of the ship; forces impinging on the outside of the field were similarly transmitted and rendered harmless. The effect was as if the vessel and all space inside its field were a single perfectly elastic body. A meteoroid, for example, on striking it rebounded--usually vaporized by the impact--and the ship, in obedience to the law of equal and opposite forces, rebounded too, but since its mass was so much greater, its deflection was negligible. The people in the _Quest III_ would have felt nothing at all of the vicious onslaught being hurled against them, save that their inertialess drive, at its normal thrust of two hundred gravities, was intentionally operated at one half of one per cent efficiency to provide the illusion of Earthly gravitation. One of the officers said shakily, "It's as if they've been lying in wait for us. But why on Earth--" "That," said the captain grimly, "is what we have to find out. Why--on Earth. At least, I suspect the answer's there."