"You have a point," he admitted, "but it isn't a good one. Young people should be afraid of dying."

"You're not."

"I'm not young. I'm thirty-five, and besides, this is my business. I've been looking at death for eleven years. I'm immune."

"I haven't your experience," she admitted, "but I have your attitude."

"What's your name?" Kramer said.

"Barton, Mary Barton."

"Hm-m-m. Well, Mary—I can't turn you down. I need you. But I could wish you had taken some other job."

"I'll survive."

He looked at her with faint admiration in his greenish eyes. "Perhaps you will," he said. "All right. As to your duties—you will be my assistant, which means you'll be a dishwasher, laboratory technician, secretary, junior pathologist, and coffee maker. I'll help you with all the jobs except the last one. I make lousy coffee." Kramer grinned, his teeth a white flash across the darkness of his face. "You'll be on call twenty-four hours a day, underpaid, overworked, and in constant danger until we lick Thurston's virus. You'll be expected to handle the jobs of three people unless I can get more help—and I doubt that I can. People stay away from here in droves. There's no future in it."

Mary smiled wryly. "Literally or figuratively?" she asked.

He chuckled. "You have a nice sense of graveyard humor," he said. "It'll help. But don't get careless. Assistants are hard to find."

She shook her head. "I won't. While I'm not afraid of dying I don't want to do it. And I have no illusions about the danger. I was briefed quite thoroughly."

"They wanted you to work upstairs?"

She nodded.

"I suppose they need help, too. Thurston's Disease has riddled the medical profession. Just don't forget that this place can be a death trap. One mistake and you've had it. Naturally, we take every precaution, but with a virus no protection is absolute. If you're careless and make errors in procedure, sooner or later one of those submicroscopic protein molecules will get into your system."

"You're still alive."

"So I am," Kramer said, "but I don't take chances. My predecessor, my secretary, my lab technician, my junior pathologist, and my dishwasher all died of Thurston's Disease." He eyed her grimly. "Still want the job?" he asked.

"I lost a husband and a three-year old son," Mary said with equal grimness. "That's why I'm here. I want to destroy the thing that killed my family. I want to do something. I want to be useful."

He nodded. "I think you can be," he said quietly.

"Mind if I smoke?" she asked. "I need some defense against that pipe of yours."

"No—go ahead. Out here it's all right, but not in the security section."

Mary took a package of cigarettes from her pocket, lit one and blew a cloud of gray smoke to mingle with the blue haze from Kramer's pipe.

"Comfortable?" Kramer asked.

She nodded.

He looked at his wrist watch. "We have half an hour before the roll tube cultures are ready for examination. That should be enough to tell you about the modern Pasteur and his mutant virus. Since your duties will primarily involve Thurston's Disease, you'd better know something about it." He settled himself more comfortably across the lab bench and went on talking in a dry schoolmasterish voice. "Alan Thurston was an immunologist at Midwestern University Medical School. Like most men in the teaching trade, he also had a research project. If it worked out, he'd be one of the great names in medicine; like Jenner, Pasteur, and Salk. The result was that he pushed it and wasn't too careful. He wanted to be famous."

"He's well known now," Mary said, "at least within the profession."

"Quite," Kramer said dryly. "He was working with gamma radiations on microorganisms, trying to produce a mutated strain of Micrococcus pyogenes that would have enhanced antigenic properties."

"Wait a minute, doctor. It's been four years since I was active in nursing. Translation,