ony, George
Martin only a step behind. After gazing up for a moment, McCarthy turned
slowly to face Dick.

"The worms? It sounds like _hundreds of them_! We better work fast, or
they'll have the whole roof down around our ears."

"No, John. We can't fight them with guns. _They have attacked every dome
on the planet!_"

When full realization came to the big Irishman, he sank slowly into a
chair. "Then what? Have you got any plan--or are we helpless?"

"We've got work to do and plenty of it. There's a slight chance of
saving the cities. I've already instructed the others."

As the three men raced toward the power plant, Dick explained. John and
George were to do the work, while he traveled from dome to dome to make
sure the people were prepared, and see that the power plants were used
as he intended.

By the time they reached the entrance of the building, John nodded, and
Barrow turned back as the other men entered the door. The first dome
people that Dick saw were told to remove everyone from the buildings,
and gather them in the open spaces of the parks. _Leaving no one within
any structure!_

The expression on his face scared them even more than the pounding of
the worms, and they hurried to obey.

Dick jumped into the nearest ground car. He couldn't be bothered
traveling on the railroads. This happened to belong to the assistant
head of the dome, whom he dispossessed. It jerked crazily across streets
and parks, while he learned to handle the controls.

An hour later Dick was back at the powerhouse in the big dome. Every
city was ready. In several places the hammering heads had broken through
the outer layers, and were banging at the translucent inner ceiling. The
creatures _had learned how_ to break through.

The first worm that attacked, while the space ship was away, either took
its time or didn't realize what was beneath the heavy metal. These
creatures were working in earnest.

Heavy insulated cables ran from the powerhouse to the nearest metal
pillars, where McCarthy and Martin were working desperately to fasten
them in place. The booming voice of the Irishman had kept the natives
back, although they crowded as close as they dared. They were really
afraid, when the hammering grew plainer with each passing minute.

When the cables were fastened, John shouted to Dick, who was waiting in
the powerhouse. He pulled a heavy switch, at the end of the wires.

The city was suddenly in complete darkness, th