Christian went up on deck and lit a cigar. He was sure that the Brains would strike back. He only hoped that Paul's energy barrier would be effective enough to hold out against their attack.

Waldo trembled and screamed and held his big head with his small hands. That high-pitched note was sounding in his head without stopping. He felt sharp pain, a red curtain was hanging before his eyes. He could not think clearly

The Brains suffered greatly. Their science could find nothing to stop that terrible noise in their heads. They could not stand that noise any longer. Some of them went mad and killed each other.

Where was the source of the noise? If the Brains knew where the noise was coming from, they could try to stop it. Waldo was sure that it was the Watcher's work. But where was the Watcher?

This was all Christian's fault, Waldo thought; Christian brought the Watcher here - and suddenly Waldo understood. The Watcher and his terrible transmitter were on the captain's yacht.

He turned to the other Brains and shouted:

"The yacht! The noise is coming from the yacht! We must attack at once. We must go there and destroy the transmitter - or perish!"

The grey dwarfs seized their weapons.

"Destroy the transmitter, Christian and the Watcher!" shouted Waldo. Every weapon must be used on the yacht!"

"But the energy barrier," said one of the Brains. "How can we break the Watcher's energy barrier?"

"We shall overload it. We shall use all the power of our weapons, and the barrier will collapse."

Christian was sitting in his chair in the cabin and smoking his cigar. Paul was lying on the bed and reading.

Suddenly a brilliant flash lit the cabin, and the yacht shook

"They are here," said Paul and stood up. "They will try to break the energy barrier. But don't worry - we are safe here."

"I am going on deck," said Christian

"Put on your dark glasses to protect your eyes," said Paul

Christian put on a pair of sun-glasses and went up the steps. Now he could see the energy barrier - a sphere of light, fifty yards across

He was surrounded by bright light. It seemed that a thousand lightnings were flashing outside the energy barrier at the same time. The air was filled with loud roar, the energy barrier was shaking as the Brains were trying to break it with their heat weapons. The water in the Thames was boiling hot, the yacht began going down and soon settled on the dry river-bed

The attack stopped, and the Brains disappeared

"I don't think they will try again," said Paul

"We must get out of here and go to a high place on the bank of the river," said Christian. "The water will come here soon."

"We'll go at once," said Paul

Together they left the yacht and went up to the high bank - and then the water came in a great wave that completely covered the yacht

"I shall visit my own time," said Paul, "to make sure that the Brains have returned there."

He touched the crystal at his belt and disappeared. In a few minutes he was standing near Christian again.

"Only a few of the Brains have returned," he said, "and Waldo is not among them. I don't know where the other, are… in another time, I suppose."

So it was not the end, Christian thought sadly.

"Have you are idea where they can be?" he asked.

Paul sighed unhappily.

"No. I suspect that they are preparing some new attack in another time. But where? It is clear that they are trying to change the course of history and become the only masters of Earth. And if they manage to change history, then, of course, our race will diappear."

The captain tried to remember all that he knew about the Brains. The Brains had decided to stop all progress by murdering research scientists. Then they concentrated on the satellite bases. Evidently, Fox was right, that the main task of the Brains was to prevent mankind from flying into space.

The future of the human race lay among the stars. But this future had a beginning - when the first star ship left Earth

"Of course!" exclaimed Christian. "The first star ship - that's what the Brains will try to destroy now!"

Paul looked at him.

"You are right," he said. "If the Brains destroy the star ship, there will be no star colonies… only the Brains and their giant women. Yes, you are right."

"We must stop them!" said Christian. "Do you know the time period?"

Paul nodded.

"We must hurry," he said.

He touched the crystals on Christian's belt and on his own.

Again there was darkness before Christian's eyes.

And then they saw the star-ship.

The Third World War had ended long ago, and Earth lay ruined. The continents were lifeless and covered with radioactive dust. The water in the oceans was poisoned.

Far in the north, in a valley which was surrounded with mountains, a few hundred people who had survived were struggling for existence. They ate what they could grow in half frozen ground and what they could get from a small number of animals which they took care of, and they were always half hungry.

From time to time storms brought death to the valley - clouds of radioactive dust - and then men fell ill and died, and women gave birth to monsters. Not long ago a new danger had appeared: the giant mutated insects had found a way into their valley.

These weak and hungry people worked at their rockets…

They had made flights to Mars and Venus, but found that it was impossible for humanity to live on these planets. They had to go to the stars. And they had built a new rocket: the new star-ship was now standing in the valley, pointing its nose to the sky.

In the shadow of the great ship a man raised his eyes and smiled.

"This is our last chance," he said. "Somewhere in space we'll find another earth - and then we can start again."

The woman standing near him said:

"And if we don't find it?"

"We must find," he answered. "There are millions of stars in space - certainly one of them must have a planet like Earth. Maybe, it will take us a long time to find it -»

"A long, long time," said the woman.

"The ship can remain in space indefinitely long," said the man. "Our children will be born in it, and their children, and the ship will go on. And at last, one day, men will land on a planet and built a new world."

All the people gathered round the star-ship. They were ready to get in.

And at that moment they saw strange figures in grey clothes with very big heads. They were approaching the ship.

Christian and Paul saw the great star-ship and the people who were standing round it. From a short distance the Brains were approaching. Waldo was walking at the head of the Brains.

Paul opened his box and pressed some buttons. The high-pitched sound came at once, rose higher and higher - and stopped. But for the Brains it did not stop - it continued in their heads.

"The Watcher again!" shouted Waldo

Paul shouted to them: There is no escape for you - return to your own time!"

Waldo fired his decapitator. "Destroy the ship!" he shouted

Christian turned to Paul. "You must do something," he said

But the Watcher hesitated: he did not want to interfere into the battle which had already begun. The Brains were firing their decapitators and killing star men, trying to get to the star-ship, the star men were defending the star-ship.

Christian raised his automatic gun and ran to Waldo. At that moment somebody shouted:

"The insects - the insects are coming!"

Christian turned. From the hills, a dark crowd of giant mutated insects were coming into the valley. They quickly approached and attacked both the Brains and the star men…