The police knew the number of Miller's car, so he could not use it. He walked quickly along the path. In the bright light of the moon he saw a workman's bicycle near the fence. Without hesitation he got on it and, leaving the Fair, rode off in the direction of Cambridge.

He travelled the whole night, and with the first light of day he decided to stop and find a place to hide. He stopped at a deserted crossroads and looked around. Through the trees growing along the road he saw a field and a river in the distance. Near the river he noticed the ruins of a descrted boat-house.

He lifted his stolen bicycle on his shoulder and crossed the field to the river. He approached the ruins of the boathouse. Tall grass growing around the door showed that nobody was using the house.

He opened the door and frightened away a rat, which quickly ran into the darkness. He saw a flight of stairs which led to a loft, and he climbed up carrying the bicycle with him. He found himself in a small room with a little window, which gave him a clear view of the approaches to the house. So if some people were coming to the house, he would see them.

Christian was satisfied. He sat down on the floor and ate some cold bacon and bread and cheese. The whole morning he was looking out of the window, but saw nobody. In the afternoon he slept a few hours.

When night fell, he set off again, and in the morning he was near Cambridge.

On the wall of a newspaper stall there was a newspaper. Christian stopped his bicycle and looked through the front page. There was a photograph of him and a text under it:

The police are looking for Captain Arthur Christian to interview him in connection with the shooting at Reading.

Christian is tall, blond, blue-eyed, with a short beard.

He is armed. The police think he may be near Cambridge.

Christian was alarmed. He decided that he must find a hiding-place at once. He could not remain in the streets during the day.

He rode on again. Soon he saw a large poster:

BURKHOLDER'S FAIR

There was a picture of the Brains and a text in red letters:

Five pounds will be given to anyone who asks a question which the Brains cannot answer.

Below the poster gave the address of the place where the Fair was located.

Christian looked around. There was a long, partly broken fence along one side of the street. Behind the fence he saw a garden and an old shed. The garden was grown with weeds, and it was clear that it was not used. Christian looked around again to make sure that nobody saw him, then took his bicycle and got into the garden through a crack in the fence.

There was a lock on the door of the shed, but Christian easily broke it and got inside. He sat down on the floor and ate some food which still remained in his bag.

During the day he slept. In the evening, when it was dark, he left the shed and rode to the place where the Burkholder Fair was located.

Jo came out of the kitchen after a late supper and walked towards her trailer. There was no moon, and the stars were covered with clouds. There was nobody around.

Then she heard a soft voice: "Jo."

She recognized Christian's voice and stopped.

"It is not safe for you here," she said in a whisper. "The whole area is watched by plain-clothes men."

Christian smiled.

"I know." He looked down at the dwarf-woman. "Jo, I didn't kill Miller."

"Of course, you didn't," she said quickly. "I never believed that for a moment. Tell me how I can help. Doctor Fox was here this morning I know where he is now. But the police are watching him."

Christian pointed to a light which was coming from one of the trailers

"Are the Brains at home?"

"I think they are," she answered. "What are you going to do?"

"I am going to speak to them," he said. "I am sure that they murdered Miller"

"Be careful, Sailor!"

Christian pressed her hand.

"Don't go near the Brains," he said. He turned and walked to the Brains' trailer

He noiselessly approached the door of the trailer, put his piece of wire into the lock and opened the door.

And again - he saw nobody!

Christian stepped inside and locked the door after himself. He sat down, looking at the door and holding his automatic gun ready. This time he was going to wait till the Brains returned.

Minutes passed. Christian thought about Fox and Jo: they both believed in him and were ready to help. It was good indeed to have such good friends. Then he thought about the Brains. Maybe now, just at this moment, they were murdering another man, and soon they would return with their murder weapon..

He didn't notice how his eyes closed. He heard some movement and opened his eyes. The Brains were standing before him - but he was sure that the door had not opened. For a long moment the Brains and Christian looked at each other.

Christian pointed his gun at them.

"You know why I am here," he said. "Speak - and remember that I can shoot you."

Suddenly Victor, the leader of the Brains, raised his hand. He was holding his murder weapon in it..

Christian jumped to his feet, quick as lightning, caught Victor by his hand and pressed it hard. The weapon fell to the floor, and Christian kicked it under the bed. He pointed his automatic at the Brains again.

"All right-speak!"

The Brains were standing and looking at him. Then Victor said quietly: "We must leave."

"You are not going to leave…"

Christian did not finish. Each Brain touched the black crystal at his waist - and disappeared. The captain was alone in the trailer, not believing his eyes. It was impossible…

Fox was right. They could not be human.

He put his hand under the bed and took out the weapon of the Brains. It was made of some hard metal

It was very important to send the weapon to Miller's chief as quickly as possible. Military Intelligence must understand who their enemies were: beings who could disappear into nothing. But he did not know if the people in Military Intelligence would believe him…

Christian walked up and down the trailer, thinking. Then he sat down at the table and wrote an account of what had happened at the Cross Keys, how he had got the Brains' weapon, and how the three Brains had disappeared before his eyes.

He smoked one of his black cigars while he was reading what he had written. Then he put his account and the weapon into a cardboard box and left the trailer. In the darkness of the night he walked noiselessly to Jo's trailer. He knocked, and Jo opened the door.

"Can you take this package to Fox?" he asked in a low voice. "Tell him to send it to Miller's chief. Tell him also that I shall be hiding at Girton: he knows that I have friends there

"I'll go now," said Jo. "Good luck, Sailor."

Christian went to the place where he had left his bicycle and rode off. Early in the morning, when it was still dark, he arrived at the village of Girton.

He got into his friends' house through the back door. It was quiet in the house, and breakfast was prepared on the table. Christian ate, then lay down on the bed which had been prepared for him.

It was late when he woke. Bright sun was shining in through the window.

On the table there was a newspaper. He read:

DECAPITATION AT CAMBRIDGE

The headless corpse of Professor Duval was found early this morning in his private study. Duval, one of the world's famous mathematicians and a lecturer at the University of Cambridge, was working on a new theory of the space-time continuum. His papers have been lost…