The house stood on a high hill. There were no houses or trees around. In a large room on the ground floor Fox and Christian sat in opposite corners; both were armed. Fox held one end of a nylon cord in his left hand. The cord was connected with a net which was hanging from the ceiling. One pull - and the net would fall.

If only one Brain appeared, they were planning to try to take him alive; more than one - and they would open fire immediately.

They were sitting and waiting. They were sure that the Brains would learn of the supposed threat to their safety. Not only newspapers published the story, but radio and television had broadcast it, too; and people were talking in the streets…

Outside the house, in the garage, two cars stood ready. Two hiding-places were prepared. One was an underground laboratory - Fox was going to use it to investigate the crystal. The other was the cellar of an empty house - and Christian was going to take the prisoner there and question him.

Suddenly a Brain appeared in the room. Christian recognized him by the scar on his nose: it was Waldo. He was alone and armed with a decapitation. He saw Christian and raised his hand with the weapon at the moment when Fox pulled the cord.

The net fell. Waldo tried to touch the black crystal on his belt, but could not do it because of the net. Christian jumped at Waldo and hit him heavily with his automatic gun. The Brain fell on the floor. Christian unfastened the Brain's belt with the crystal and gave it to Fox.

"Go!" he said. "I'll take care of Waldo."

Doctor Fox put the belt with its black crystal into a metal box and locked the box. Then he quickly left the room.

Christian lit a cigar. Then he lifted Waldo from the floor, threw him over his shoulder and went out. He saw Fox's car in the distance. Reaching the garage, he put Waldo into the other car, got in himself, started the engine and drove off.

Waldo spat.

All the way to the hiding-place he spat and cursed Christian - and there were some words in his speech Which Christian did not understand. These words sounded English, but he did not know them.

The cellar of the house where Christian brought Waldo was empty. In the middle was a big barrel filled with water. It was very heavy, and Christian tied Waldo to it. In one corner of the cellar there were stone steps which led to a massive door. Christian had locked this door, and the key was in his pocket.

The Brain's decapitator was pushed under Christian's belt. He looked at his prisoner, holding his automatic in his hand.

"Listen," he said. "You are going to answer my questions. We are quite alone, and I shall make you talk."

Waldo spat again.

Christian lit a cigar and held it close to Waldo's face.

"You will be sorry, Christian," said Waldo. "You will answer for it."

"Answer me!" said the captain. "I'm losing patience… Where do you come from? How many of you are there? How do your crystals work?"

He received no answer. He raised his hand and struck Waldo a heavy blow on his face.

"Talk, I tell you!"

He took the Brain's weapon from under his belt and pointed it at him.

"I am giving you three minutes," he said. "If you don't speak and answer my questions, I'll use your weapon on you. I'll decapitate you."

The telephone began to ring.

Christian was surprised. Only Fox knew that he was there. He took the receiver.

"Chris? Fox here. The crystal has disappeared. I kept looking at the box all the way here, and when I unlocked the box just now, it was empty. There was nobody near me. But the belt with the crystal has disappeared!"

Somewhere in the south of England a conference was taking place. A group of scientists were sitting and standing round the laboratory table. On the table there were parts of the weapon which Christian had seized from the Brains and sent to Military Intelligence.

The Minister of War was looking at the parts of the weapon attentively.

"The weapon worked on quite a new principle," said the leader of the research group. "By some method - we don't understand it - power is taken directly from the atmosphere and changed into heat energy. This heat energy is emitted in a concentrated ray, which annihilates any material form."

The Minister of War thought.

"Can we make such a weapon?" he asked.

Outside the laboratory there was a strong guard of soldiers. They were ready for a possible attack of the Brains.

Suddenly the guard commander saw a great cloud of flame and smoke rising over the laboratory. A few minutes later nothing remained of the laboratory and the people who were inside it.

The guard commander sent a telephone message to Downing Street.

The Prime Minister looked tired. There were dark circles round his eyes, and his face was pale.

"It's a bad business," he said, "and I can't see the end of it."

The Old Man was sitting at the table opposite the Prime Minister.

"Our only hope is Captain Christian, sir," he said. "If his plan works, we may get useful information."

"True," sighed the Prime Minister. "And meanwhile the decapitations continue. We are losing the best men every day, and it's the same all over the world."

The Old Man said nothing, because he did not know what to say.

"And now the Minister of War," continued the Prime Minister. "It seems impossible! Only yesterday I spoke to him -»

"I am sorry," said the Old Man. "I know he was a personal friend of yours."

There was a short silence.

"I am waiting for news from New York," said the Prime Minister. "As you know, the United Nations are holding an emergency meeting now…"

The Secretary-General called again for order. "Gentlemen, please, the delegate from Great Britain has the floor."

It was noisy in the great hall. Delegates jumped from their seats and cried. Everybody accused everybody. The Asian Federacy accused Britain. The United States accused Russia. It seemed that the delegates would begin fighting any moment.

At last the British delegate was able to speak.

"This is no time for quarrelling among ourselves," he said. "An invasion from space is threatening us-"

There was a great noise again.

"- an invasion from space," continued the British delegate. "Our civilization is in danger. We must co-operate-"

It was useless. All the delegates were shouting again, and the Secretary-General declared the meeting closed.

A man was decapitated in New South Wales, three in Yucatan, four in Quebec. The murders continued in Africa, Pakistan and Denmark. Scientists who did original research were murdered all over the world.

And only one man had a contract with the enemy.

Christian put down the receiver, walked up to the Brain, stopped in front of him and raised the decapitator.

"Wait," said Waldo.

"No, I won't wait," said the captain. "Speak, or I'll shoot."

"Don't shoot! I'll answer your questions. We come from-"

Suddenly they were not alone. About ten Brains were standing around Christian, grey, dwarf-like figures, each armed with a decapitator.

Waldo laughed.

"That's the end, Captain…" He gave a command: "Take him alive - I want him alive!"

The next moment Christian was seized by a lot of hands, something heavy struck him on the head, and he fell on the floor.

"You interfered and spoiled our plans," said Waldo. "And for this you must die. But it will not be a pleasant death - I've something special for you. I am taking you back with me."

He took a belt with a black crystal from one of the Brains and fastened it round Christian's waist.