"Would you care for a lift home, Doctor Alcala?" The offer was made with the utmost suavity.

Alcala hesitated fractionally. "Why, yes, thank you." It would not do to give the investigator any reason for suspicion by refusing.

As the 'copter lifted into the air, Camba spoke with a more friendly note in his voice, as if he humored a child. "Come, Alcala, you're a doctor dedicated to saving lives. How can you find sympathy for a murderer?"

Alcala sat in the dark, looking through the windshield down at the bright street falling away below. "I'm not a practicing medico; only one night a week do I come to the hospital. I'm a research man. I don't try to save individual lives. I'm dedicated to improving the average life, the average health. Can you understand that? Individuals may be sick and individuals may die, but the average lives on. And if the average is better, then I'm satisfied."

The 'copter flew on. There was no answer.

"I'm not good with words," said Alcala. Then, taking out his pen-knife and unfolding it, he said, "Watch!" He put his index finger on the altimeter dial, where there was light, and pressed the blade against the flesh between his finger and his thumb. He increased the pressure until the flesh stood out white on either side of the blade, bending, but not cut.

"Three generations back, this pressure would have gone right through the hand." He took away the blade and there was only a very tiny cut. Putting the knife away, he brought out his lighter. The blue flame was steady and hot. Alcala held it close to the dashboard and put his finger directly over it, counting patiently, "One, two, three, four, five—" He pulled the lighter back, snapping it shut.