Barbara held out her hand.

"I don't think we shall meet again, Captain," she said, "so I wish you good luck" To Paul she said: "Take care of yourself."

Paul took a small metal box. Then he touched the crystals on his and Christian's belts. There was darkness again. Christian wondered what was waiting for him in his own time.

Christian and Paul were sitting at the table in front of the Old Man, head of Military Intelligence.

"Glad to see you, Captain," said the Old Man. "And your friends. I hope you have brought good news. Cigar?"

"Thanks." Christian took a cigar from the wooden box and lighted it. "This is one thing they haven't got in the future," he said with pleasure.

The Old Man was looking at Paul.

"So you are a man from the future?

"One hundred thousand years in the future," said Paul.

Christian told his story. The Old Man listened attentively and did not interrupt him.

You've done well, Captain," he said when Christian finished. "At least we know now who are our enemies." He turned to Paul. "Do you think you cap help us?"

Paul nodded.

"I think so," he said. "It won't be easy, but I think I can do something."

"Good," said the Old Man. "We will give you any help you need. Our situation is desperate," he continued. "We cannot do anything with the Brains because they disappear immediately. And appear in other places, destroy, kill, and disappear again. I have here - " he lifted some papers from the table, "details of murders in all parts of the world - Cuba, Turkey, Russia, other countries. And all the victims were scientists. All our rocket bases have been destroyed. It is clear that they want to stop us from getting into space."

"It will all be different now," said Christian.

"I hope so," said the Old Man. "By the way," he continued, "I have let your friend Fox know that you have come back. He wants to see you. I think he has a surprise for you -»

Christian smiled.

"And I have a surprise for him - Paul"

The Old Man said: "It will be better if Mr. Paul stays with us."

Paul stood up

"I am going with Captain Christian," he said

The Old Man opened his mouth to speak - and changed his mind.

Christian and Paul came to Doctor Fox's house in a taxi. The door opened, and Doctor Fox jumped out and shook Christian's hand.

"Chris! It's good to see you again… come in, come in!"

He ran along the corridor. At the door of the living room he stopped.

"Surprise!" he shouted.

Christian saw a small figure with dark hair.

"Why, Jo!" he exclaimed.

"Mrs. Fox," the doctor said proudly. "We have been married a whole week."

Christian laughed.

"Well, congratulations!"

"Welcome back, Sailor," said Jo.

"This is Paul," said Christian "Paul, these are two good friends of mine."

Paul stepped forward, smiling.

Fox and Jo were listening with great interest while Christian was telling them about his adventures.

"The Brains will find you," said Paul to Christian when they left Fox's house. "You have interfered with their plans too often, and they will not forgive you that. They will come to you soon, I am sure. And when they come, I want to talk to them."

They drove to Reading, where the captain's yacht was still standing in the quiet place in the Thames.

In the cabin of the yacht Paul put his metal box on the table and opened it.

"You need not be afraid, Captain," he said. "My energy barrier will protect you."

Christian pulled out a box of shells and loaded his automatic.

"If the Brains come," he said, "let them be afraid."

Paul looked at him.

"There will be no more shooting, please," he said. "I don't want any more killing."

They had visitors the next day.

Christian was standing on deck and smoking his cigar.

Suddenly he was no longer alone. A voice said:

"At last, Captain!"

He turned and saw many big bald heads. The Brains! One of them was Waldo. He raised his decapitator. There was a flash - and nothing happened. Paul's energy barrier protected Christian.

Waldo was shaken.

There is a Watcher here," he said - and then Paul came up on deck.

Waldo spat. All the Brains were standing and looking at Paul

"You must return to the future," said Paul quietly. "If you don't. I shall have to use force."

Waldo laughed.

"It is well known," he said, "that the Watchers do not kill. You can do nothing. We are not afraid of you!"

Christian was angry. He threw away his cigar and raised his automatic.

"I am not a Watcher," he said," and I kill."

Paul turned his head.

"It is useless to shoot, Captain," he said. "My energy barrier works both ways - it will protect them, too"

"I'll kill you one day!" shouted Waldo to Christian. "You shan't always escape me."

Paul looked at Waldo.

"Your time machine is in the hands of the Watchers," he said. "You are free only while you remain here - and I shall make this age unbearable for you."

Waldo was looking at him with angry eyes.

"You Watchers have done what you liked too long," he said. "You have upset our plan - but that won't save you. We'll see what happens -»

Paul interrupted: "I shall not allow you to interfere with the natural course of history. Return to your own time, and I'll do what I can to help you."

"Help!" Waldo spat. "We want no help from the Watchers. You will see what will happen - we shall destroy Earth completely!"

Paul looked troubled, and Christian said: "Switch off your barrier and shoot them!"

"He won't do that!" Waldo laughed. "A Watcher will never kill!" He touched the crystal on his belt and disappeared with the rest of the Brains.

Christian turned to Paul.

"You heard what he said - the'll destroy Earth. There won't be any future if we don't kill them. There is no other way."

Paul sighed unhappily.

"There must be another way," he said.

He went down into the cabin. He took some wires out of his metal box and began making some complicated device

"It will be good if you inform your government of this new threat of the Brains," he said to Christian. "It will take me some time to build the weapon which I am making, and who knows what the Brains may do during this time."

"This weapon which you are making - will it stop the Brains?"

"Yes, it will stop them."

Christian ran up on deck, jumped on the shore and hurried to the nearest telephone.

The Imperial Technical Institute occupied a very large territory; hundreds of specialists worked in its laboratories and workshops; and its stores contained materials for production of anything from shampoo to an atomic bomb.

The Brains came there at night. The guards were decapitated at once, and behind the Institute's massive walls the Brains began making weapons of destruction.

They worked hard. In the stores of the Institute they found all the necessary materials. The Brains were very many, and they all were clever specialists, so their work went on very fast.