Like a clap of thunder the noise reverberated through the metal hull of the sphere. Kraag started violently, and only the bunk straps kept him from rocketing to the ceiling. Again: CRASH! And Kraag could feel the sphere shiver with the blow. He switched on the lights just as another terrific crash sounded. This time he could see everything on the central deck quiver with the impact. One of the four small ports around the central deck was uncovered, and the light threw a beam out into the black night of the asteroid. It brought a temporary cessation of the regular blows. During the interval, Kraag unstrapped himself and tumbled up to the control room, to switch on the communications system. "Jonner!" he shouted. "Jonner, what in hell?" "I'm not deaf," said the loudspeaker resentfully. "Give me a chance to turn down my volume, if you're going to holler." "What the devil are you doing out there, Jonner?" "What I promised you. I'm coming in after you." Kraag swore. "I'm going to blow you off the damned planet," he threatened, and leaped for the gun rack. "You'll have to come outside to do it," reminded Jonner. "If you try to shoot through the ports, you'll save me a lot of work." Kraag raced up and down the sphere twice before he had sense enough to turn out all the lights and use the searchlight. Then he located Jonner, clinging to the sphere outside the astrodome on the navigation deck. Jonner had a sledge hammer from the ship's cargo section in his hand. Jonner grinned at him and moved quickly out of the searchlight's beam. Ten seconds later, another thunderous crash sounded, apparently from the other side of the sphere. Kraag swung the light in a circle, but Jonner could move faster than the beam. Hastily, Kraag made another tour of the sphere, this time closing all the metal covers over the ports. When he reached the control room, Jonner's voice was calling him over the loudspeaker, repeating his name every few seconds. "What do you want?"