"Leavitt has epilepsy?"

"That's right."

Stone said, "He must not have known. He must not have realized."

And then Stone remembered the request for a repeat electroencephalogram.

"Oh," Hall said, "he knew, all right. He was avoiding flashing lights, which will bring on an attack. I'm sure he knew. I'm sure he has attacks where he suddenly doesn't know what happened to him, where he just loses a few minutes from his life and can't remember what went on."

"Is he all right?"

"We'll keep him sedated."

Stone said, "We've got pure oxygen running into Burton. That should help him, until we know something more." Stone flicked off the microphone button connecting voice transmission to Burton. "Actually, it will take several minutes to hook in, but I've told him we've already started. He's sealed off in there, so the infection is stopped at that point. The rest of the base is okay, at least."

Hall said, "How did it happen? The contamination."

"Seal must have broken," Stone said. In a lower voice, he added, "We knew it would, sooner or later. All isolation units break down after a certain time."

Hall said, "You think it was just a random event?"

"Yes," Stone said. "Just an accident. So many seals, so much rubber, of such-and-such a thickness. They'd all break, given time. Burton happened to be there when one went."

Hall didn't see it so simply. He looked in at Burton, who was breathing rapidly, his chest heaving in terror.

Hall said, "How long has it been?"

Stone looked up at the stop-clocks. The stop-clocks were special timing clocks that automatically cut in during emergencies. The stop-clocks were now timing the period since the seal broke.

"Four minutes."

Hall said, "Burton's still alive."

"Yes, thank God." And then Stone frowned. He realized the point.

"Why," Hall said, "is he still alive?"

"The oxygen . . ."

"You said yourself the oxygen isn't running yet. What's protecting Burton?"

At that moment, Burton said over the intercom, "Listen. I want you to try something for me."

Stone flicked on the microphone. "What?"

"Kalocin," Burton said.

"No." Stone's reaction was immediate.

"Dammit, it's my life."

"No," Stone said.

Hall said, "Maybe we should try—"

"Absolutely not. We don't dare. Not even once."

Kalocin was perhaps the best-kept American secret of the last decade. Kalocin was a drug developed by Jensen Pharmaceuticals in the spring of 1965, an experimental chemical designated UJ-44759W, or K-9 in the short abbreviation. It had been found as a result of routine screening tests employed by Jensen for all new compounds.

Like most pharmaceutical companies, Jensen tested all new drugs with a scatter approach, running the compounds through a standard battery of tests designed to pick up any significant biologic activity. These tests were run on laboratory animals—rats, dogs, and monkeys. There were twenty-four tests in all.

Jensen found something rather peculiar about K-9. It inhibited growth. An infant animal given the drug never attained full adult size.

This discovery prompted further tests, which produced even more intriguing results. The drug, Jensen learned, inhibited metaplasia, the shift of normal body cells to a new and bizarre form, a precursor to cancer. Jensen became excited, and put the drug through intensive programs of study.