"What have you got?" asked John.

"Enough to make quite an interesting soup," said Phillip.

He put the bottles down and let the men examine the labels, then he gathered them back again and clipped the container shut again.

The men left the room and climbed into their suits. Soon they were driving slowly out to the flat again.

Everything was as it had been the day before, only the dust had settled. Phillip drove slowly, so as not to raise too much obscuring particles, and stopped the small Vehicle beside the thin outline of the square they had all nicknamed 'the door'. None of the men really expected it be a door, neither did they really expect it to open. It was their way of making light of something which, had it been taken too seriously, would have crushed them.

Phillip began to test different substances on the flat. He used a spray gun, loading it each time with the contents of each bottle. The mist from the gun shot outwards and billowed slightly in the frigid airless atmosphere, leaving a discoloration along the line at Phillip's feet.

Six tests showed no reaction. The seventh test did. Phillip stopped, startled, and bent over slightly to have a closer look. His worst fears had come true. The fluid had caused a slight fluorescence along the line where it had struck.

He checked the bottle, hoping he was wrong. Human blood. He shuddered. All the other samples had been animal, but the door recognized human.

EIGHT

Phillip beckoned with his hand, and the three men climbed down from their machines, and walked over. They took a minute to cover the wide, flat surface, which reflected the harsh sunlight like a pcncil. The moment they arrived they realized what had happened.

"Stand back!" ordered Phillip, for once in a long time actually feeling as if he was in some sort of control. Giving orders some how relieved the tension and made the job more 'human'.

The spray-gun fired again, finishing off its circuit around the perimeter of the square. The line was now glowing softly, a subtle contrast to the polarized sunlight effect, and the area of the square moved downwards slightly. Involuntarily, all four men stepped