He finally spoke with hesitation. "I have bad news for you. The Martins will have to occupy an apartment in this city for a while. Their dome is out of order. Trouble developed soon after the ship left here, on this trip, and over a thousand people were killed. Every other city is overcrowded with refugees. "It started with a strange banging on top of the dome, which kept increasing. No one knew what the trouble was or how to stop it, so they waited to see what happened. It didn't sound as if the ceiling was going to fall--but as if the banging came from _outside_! It was several migs before they knew the cause. "When a large section crashed to the ground, it was a complete surprise, and caught the inhabitants unprepared. Soon the air was mixing with the poison gases from outside. People tried to escape, and most of them did. All except those that fell unconscious from the gas. "Before the last of them reached the tunnel, green things dropped to the ground, and started after those who remained. They had to close the doors between the cities to keep the creatures from entering this dome. It is the first time that anything has happened to my people, and we don't know what it could be." For a long time the earthmen remained silent. The troubles of this civilization had been dumped into their laps already--in the form of a terrible calamity. It sounded _almost_ as if some kind of life forms had broken through the domes _from the outside_! Perhaps there was more danger than could be imagined. One dome had been injured, if not destroyed, and others might follow! A meeting of the earthmen was called immediately, much to their surprise. Dick dared not let conditions stay as they were, for fear of future trouble. Action must be taken at once. "We don't know what we're facing, but the fate of the race as well as our own lives, seem to be in danger. The break in the dome might have been accident, and the moving forms the imagination of fear. But we know that over a thousand people were killed--whatever caused the trouble!" The men went back to their domes to rest, and plan some means of entering the deserted city, but were disturbed before they had time for sleep. _The agricultural dome had been attacked!_ The pounding had begun within a short time of their arrival. One thing was certain, the injured dome had been _attacked_! It was not accident that the metal ceiling fell. _There were living beings in the gases outside their civilization!_ The first dome had been attacked just after the space ship left for the earth, and this attack came just after its return to the domes. There was little doubt that movement of the ship had disturbed the serenity of existence. Perhaps the gas creatures hadn't known what was beneath the metal hives until the ship appeared.