It was always night on Martha, but Mark broke up his time into mornings, afternoons and evenings. Their life followed a simple routine. Breakfast, from vegetables and Mark's canned store. Then the robot would work in the fields, and the plants grew used to his touch. Mark would repair the pump, check the water supply, and straighten up the immaculate shack. Lunch, and the robot's chores were usually finished.

The two would sit on the packing case and watch the stars. They would talk until supper, and sometimes late into the endless night.

In time, Mark built more complicated conversations into Charles. He couldn't give the robot free choice, of course, but he managed a pretty close approximation of it. Slowly, Charles' personality emerged. But it was strikingly different from Mark's.

Where Mark was querulous, Charles was calm. Mark was sardonic, Charles was naive. Mark was a cynic, Charles was an idealist. Mark was often sad; Charles was forever content.

And in time, Mark forgot he had built the answers into Charles. He accepted the robot as a friend, of about his own age. A friend of long years' standing.

"The thing I don't understand," Mark would say, "is why a man like you wants to live here. I mean, it's all right for me. No one cares about me, and I never gave much of a damn about anyone. But why you?"

"Here I have a whole world," Charles would reply, "where on Earth I had to share with billions. I have the stars, bigger and brighter than on Earth. I have all space around me, close, like still waters. And I have you, Mark."

"Now, don't go getting sentimental on me—"

"I'm not. Friendship counts. Love was lost long ago, Mark. The love of a girl named Martha, whom neither of us ever met. And that's a pity. But friendship remains, and the eternal night."

"You're a bloody poet," Mark would say, half admiringly. "A poor poet."

Time passed unnoticed by the stars, and the air pump hissed and clanked and leaked. Mark was fixing it constantly, but the air of Martha became increasingly rare. Although Charles labored in the fields, the crops, deprived of sufficient air, died.