"But that," protested Gary, "will produce more energy. Their little universe will be destroyed."

"No," declared the Engineer, "because they will merge their space-time continuum with the continuum of our universe as soon as the two come together. They will immediately become a part of our universe."

"You told them how to create a hypersphere?" asked Herb.

"I did," said the Engineer. "And it will save the people of that other universe. They had tried many things, had worked out theories and new branches of mathematics in their efforts to escape. They discovered many things that we do not know, but they never thought of budding out from their universe. They apparently are a mechanistic people, a people very much like we Engineers. They seem to have lost that vital spark of imagination with which your people are so well supplied."

"My Lord," said Gary, "think of it! Imagination saving the people of another universe. The imagination of a little third-rate race that hasn't even started really using its imagination yet."

"You are right," declared the Engineer, "and in the aeons to come that imagination will make your race the masters of the entire universe."

"Prophesy," said Gary.

"I know," said the Engineer.

"There's just one thing," said Herb. "How is that other universe going to be destroyed?"

"We are going to destroy it," said the Engineer, "in exactly the same way we destroyed the Hellhounds."

CHAPTER Seventeen

Tommy sat in the pilot's seat and urged the ship slowly forward, using rocket blast after rocket blast to keep it on its course.

"You have to fight to stand still here," he gritted between his teeth. "A man can't tell just where he is. There doesn't seem to be any direction, nothing to orient oneself."

"Of course not," rumbled Kingsley. "We're in a sort of place no other man has ever been. We're right out in the area where space and time are breaking down, where lines of force are all distorted, where everything is jumbled and broken up."

"The edge of the universe," said Caroline.

Gary stared out through the vision plate. There was nothing to see, nothing but a deep blue void that queerly seemed alive with a deep intensity of life.

He turned from the panel and asked the Engineer:

"Any signs of energy yet?"

"Faint signs," said the Engineer, bending lower to peer at the dial set in a detector instrument. "Very faint signs. The other universe is almost upon us now and the lines of force are just beginning to make themselves felt."

"How much longer will it take?" asked Kingsley.

"I cannot tell," said the Engineer. "We know very little about the laws out here. It may be a very short while or it may be some time as yet."

"Well," said Herb, "the fireworks can start any time now. The folks from the other universe have crossed safely and there's no reason for the other universe to exist. We can blast it any time we want to."

"Gary," said Kingsley, "you and Herb better get over to those guns. We may want action fast."

Gary nodded and walked to the controls of a disintegrator gun. He slid into the seat back of the controls and reached out a hand to grasp the swivel butt. He swung it back and forth, knew that outside the ship the grim muzzle of the weapon was swinging in a wide arc.

Through the tiny port in front of him he could see the blue intensity of the void in which they moved.

Out here time and space were thinning down and breaking up. Like a boat riding on the surface of a heaving sea, they were riding the very rim of the universe, their ship tossed about by the shifting, twisting co-ordinates of force.

Out there somewhere, very close, was the mysterious inter-space. Close, too, invisible in all its immensity, was another universe. An old and tottering universe from which its inhabitants had fled, a dying universe that had been sentenced to death so that a younger universe might live.

In just a few minutes now the space between the universes would begin to fill with a charge of that terrible timeless, formless energy. Slowly it would begin seeping into the two universes, slowly at first and then faster and faster, increasing their mass, dooming them to almost instant destruction.

But before that could happen, the disintegrator ray, the most terrible form of energy known to the Engineers, would blast out into that field of latent energy, would sweep outward toward that other approaching universe.

Instantly the field of energy would be turned into the terrific power of the disintegrator ray, but millions of times more powerful than the ray itself… a blinding sheet of energy that would stop at nothing, that would smash the very mold of time and space, would destroy matter and cancel other energy. And this sheet of energy would smash its way into the other universe.

And when that happened, the energy field, draining all its energy into the disintegrator blast, would be diverted from the younger universe, would turn in full force upon the one to be destroyed.

Staggering under the onrush of such a fierce storm of energy, the old universe would start contracting. Its mass would build up, faster and faster, as the fifth-dimensional energy, riding on the beams of the disintegrator guns, hurled itself into its space-time frame.

Gary wiped his brow with the back of his hand.

That was the way Caroline and the Engineer had figured it out. He hoped that it would work. And yet it seemed impossible that a tiny ship, two tiny guns manned by the puny members of the human race, could utterly annihilate a universe, an unimaginably massive space-time matrix.

Yet he had seen the beam of a tiny flashlight, crystalizing the energy of the eternal dimension, blast out of existence, in the twinkling of an eye, a mighty fleet of warships protected by heavy screens, armored against vicious bombs, impregnable to anything… to anything except the flashlight in the hands of a wisp of a girl.

Remembering that, it was easier to believe that the disintegrators, crystalizing a much vaster field of energy, might accomplish the destruction of a universe. For it wasn't the guns themselves that would do the job, but the direction of all the energy into the other universe, energy rising on the million-mile front set up by the fanning guns.

"The field is building up," said Caroline. "Be ready." Gary grinned at her. "We'll fire when we see the whites of their eyes," he said.

He racked his brain for the origin of that sentence. Something out of history. Something out of the dim old legends of the past. A folk tale of some mighty battle of the ancient days.

He shrugged his shoulders. The story, whatever it might be, probably wasn't true, anyhow. So few of the ancient legends were. Just another story to be told of a black night in the chimney corner when the wind howled around the eaves and the rain dripped on the roof.

His eyes went to the port again, stared out into the misty blue, the blue that seemed to throb with vibrant life.

They had to wait. Wait until the energy had built up to a point where it would be effective. But not too long. For if they waited too long, it might pour into their own universe and wipe them out.

"Get ready," thundered Kingsley, and Gary's hand went out to the switch that would loosen the blast of the disintegrator. His fingers gripped the switch tightly, tensed, ready for action.

"Give it to "em," Kingsley roared, and Gary snapped the switch.

With both hands he swung the swivel back and forth, back and forth. Beside him, he knew, Herb was doing the same.

Outside the port blossomed a maelstrom of fiery light, a blinding, vicious flare of light that seemed to leap and writhe and then become a solid sheet of flame. A solid sheet of flame that drove on and on, leaping outward, bringing doom to a worn-out universe.