Here and there were railings with steps going down. Like subway entrances, Odin thought, except they were more elaborately carved. These steps went down to tier after tier of labyrinths. It was a skyscraper-city turned upside down, Odin gathered from Val’s explanations. The first level below the city was made up of factories and machine shops. The next was where plants, flowers, and trees were forced, producing the city’s food. Below that, for nearly a thousand feet, were the living quarters of the people.

The ground-level of the city was in reality a beautiful park. During the day, Val explained, it was busy with street-vendors, open-air schools, theaters, and thousands who came up from underground to drink the air and the sun.

Now, it was nearly empty. The columns were evenly spaced and at a spot exactly between each two columns was a great cresset of stone. At the top of each cresset were flickering flames that burned without leaving any smoke. “Like stone tulips with petals of flame,” Gunnar said as he looked at them. They stood nearly twelve feet high. Their pedestals were broad; their stems were nearly a foot thick, nearly a yard across. Their flames were violet, tipped with blue. They made a beautiful sight, but it did not matter. For within less than an hour this lovely park with its carved columns and tulip-shaped cressets of fire was turned into a shambles.

They had not gone a quarter of a mile before a guard hailed them. A score of guns popped like opened bottles and the guard died before the echo of his voice was gone. But his cry was taken up by others. And now Odin saw that up there in the spider-web framework that held the dome were hundreds of little cubicles—all manned.

Shafts of flame darted through the dim-lit area. Bullets whizzed. Ato’s needle-nosed machines began to whine and the metal in the guards’ cubicles grew red-hot and melted. Charred bodies came tumbling down. Men came pouring out of the subway entrances. There was a crashing and grinding as hidden elevators brought weapons of death to the surface. The fires in the cressets danced higher. They fought now in mid-day light.

There was a blast nearby that nearly burst Odin’s eardrums. A crash of flame that half-blinded him. A gun-crew screamed and died as one of the needle-nosed machines melted into puddles of steel. One by one these guns exploded, taking their crews with them. But even as they died, they littered the streets with the bodies of those who were pouring up from the depths of the city. Even as one melted, its needle-nose swung upward and its beam cut through girders as though they were soft cheese. There was an awful grating sound as the heavy dome sagged a few inches. Splinters of glass and plastic rained down upon invader and defender alike.

Guns burst in men’s hands—or turned to soft wax. The machine guns grew red-hot and melted. Ato sent his swirling bombs toward the enemy. The scythe-blades dripped as they cut swaths through massed rows of human flesh. But from far down the street a swarm of red sparks came rushing at the bombs like hornets. They swirled about them, humming angrily. And then the bombs and the hornet-sparks were gone.

Odin learned that the toadstool-shaped weapon which Val’s men carried was a defense against the lancing beams from the glassy tubes. So one by one the weapons of offense and the weapons of defense fell apart. Sirens were screaming within the city. Hordes were still arriving from the depths below.

Ato had set up a huge, slowly-whirling globe that was studded with spines. As it turned upon its axis, it emitted a strange pulsing light. As the defenders came rushing up the stairways to the upper world, the guns at their belts exploded in furious heat. They died by the hundreds at those entrances. They filled the stairways and the halls below. Screams from seared throats drowned out the noise of battle. The stench of burned flesh and blood was now so heavy that it was hard to breathe. Another wild shell crashed into the spider-web framework of the dome. It sagged again with a shriek and a groan of protest. And once more a rain of glass showered down upon them.

The defenders cleared the choked stairways and came on—dying at the entrances and falling back and blocking the stairs again.