For the hand had two thumbs and a single finger, almost as if a bird claw had decided to turn into a hand.

"Nor like this." asked the other, standing up and letting down his trousers.

"Nor like that," said Doc, more shaken than he'd been in many years of practice.

"Then," said the alien, zipping up his trousers, "I think that it is settled."

He sat down again and calmly crossed his knees.

"If you mean I accept you as an alien," said Doc, "I sup-pose I do. Although it's not an easy thing."

"I suppose it is not. It comes as quite a shock."

Doc pa.s.sed a hand across his brow. "Yes, a shock, of course. But there are other points..."

"You mean the language," said the alien. "And my knowl-edge of your customs."

"That's part of it, naturally.""We've studied you," the alien said. "We've spent some time on you. Not you alone, of course..."

"But you talk so well," protested Doc. "Like a well-edu-cated foreigner."

"And that, of course," the other said, "is what exactly I am."

"Why, yes, I guess you are," said Doc. "I hadn't thought of it."

"I am not glib," said the alien. "I know a lot of words, but I use them incorrect. And my vocabulary is restricted to just the common speech. On matters of great technicality, I will not be proficient."

Doc walked around behind his desk and sat down rather limply. "All right,"

he said, 'let's have the rest of it. I accept you as an alien. Now tell me the other answer. Just why are you here?"

And he was surprised beyond all reason that he could approach the situation as calmly as he had. In a little while, he knew, when he had time to think it over, he would get the shakes.

"You're a doctor," said the alien. "You are a healer of your race."

"Yes," said Doc. "I am one of many healers."

"You work very hard to make the unwell well. You mend the broken flesh.

You hold off death..."

"We try. Sometimes we don't succeed."

"You have many ailments. You have the cancer and the heart attacks and colds and many other things-I do not find the word."

"Diseases," Doc supplied.

"Disease. That is it. You will pardon my shortcomings in the tongue."

"Let's cut the niceties," suggested Doc. "Let's get on with it."

"It is not right," the alien said, "to have all these diseases. It is not nice. It is an awful thing,"

"We have less than we had at one time. We've licked a lot of them."

"And, of course," the alien said, "you make your living with them."

"What's that you said!" yelped Doc.

"You will be tolerant of me if I misunderstand. An eco-nomic system is a hard thing to get into one's head."

"I know what you mean," growled Doc, "but let me tell you, sir..." But what was the use of it, he thought. This being was thinking the self-same thingthat many humans thought.

"I would like to point out to you," he said, starting over once again, "that the medical profession is working hard to conquer those diseases you are talking of. We are doing all we can to destroy our own jobs."

"That is fine," the alien said. "It is what I thought, but it did not square with your planet's business sense. I take it, then, you would not be averse to seeing all disease destroyed."

"Now, look here," said Doc, having had enough of it, "I don't know what you are getting at. But I am hungry and I am tired and if you want to sit here threshing out philoso-phies..."

"Philosophies," said the alien. "Oh, not philosophies. I am practical. I have come to offer an end of all diseases."

They sat in silence for a moment, then Doc stirred half protestingly and said, "Perhaps I misunderstood you, but I thought you said..."

"I have a method, a development, a find-I do not catch the word-that will destroy all diseases."

"A vaccine," said Old Doc.

"That's the word. Except it is different in some ways than the vaccine you are thinking."

"Cancer?" Doc asked.

The alien nodded. "Cancer and the common cold and all the others of them.

You name it and it's gone."

"Heart," said Doc. "You can't vaccinate for heart."

"That, too," the alien said. "It does not really vaccinate. It makes the body strong. It makes the body right. Like tuning up a motor and making it like new. The motor will wear out in time, but it will function until it is worn out entirely."

Doc stared hard at the alien. "Sir," he said, "this is not the sort of thing one should joke about."

"I am not joking," said the alien.

"And this vaccine-it will work on humans? It has no side effects?"

"I am sure it will. We have studied your-your-the way your bodies work."

"Metabolism is the word you want."

"Thank you," said the alien."And the price?" asked Doc.

"There is no price," the alien said. "We are giving it to you."

"Completely free of charge? Surely there must be..."

"Without any charge," the alien said. "Without any strings." He got up from the chair. He took a flat box from his pocket and walked over to the desk.

He placed it upon the desk and pressed its side and the top sprang open.

Inside of it were pads-like surgical pads, but they were not made of cloth.

Doc reached out, then halted his hand just above the box. "May I?" he asked.

"Yes, certainly. You only touch the tops." Doc gingerly lifted out one of the pads and laid it on the desk. He kneaded it with a skittish finger and there was liquid in the pad. He could feel the liquid squish as he pressed the pad. He turned it over carefully and the underside of it was rough and corrugated, as if it were a mouthful of tiny, vicious teeth.

"You apply the rough side to the body of the patient," said the alien. "It seizes on the patient. It becomes a part of him. The body absorbs the vaccine and the pad drops off."

"And that is all there's to it?"

"That is all," the alien said.

Doc lifted the pad between two cautious fingers and dropped it back into the box. He looked up at the alien. "But why?" he asked. "Why are you giving this to us?"

"You do not know," the alien said. "You really do not know."

"No, I don't," said Doc.

The alien's eyes suddenly were old and weary and he said: "In another million years you will."

"Not me," said Doc.

"In another million years," the alien said, "you'll do the same yourself, but it will be something different. And then someone will ask you, and you won't be able to answer any more than I am now."

If it was a rebuke, it was a very gentle one. Doc tried to decide if it were or not. He let the matter drop.

"Can you tell me what is in it?" he asked, gesturing at the pad.

"I can give you the descriptive formula, but it would be in our terms. It would be gibberish.""You won't be offended if I try these out?"

"I'd be disappointed if you didn't," said the alien. "I would not expect your faith to extend so far. It would be simple-minded."

He shut the box and pushed it closer to Old Doc. He turned and strode toward the door.

Doc rose ponderously to his feet. "Now, wait a minute there!" he bellowed.

"I'll see you in a week or two," the alien said. He went out and closed the door behind him.

Doc sat down suddenly in the chair and stared at the box upon the desk. He reached out and touched it and it was really there. He pressed the side of it and the lid popped open and the pads were there, inside.

He tried to fight his way back to sanity, to conservative and solid ground, to a proper-and a human-viewpoint. "It's all hogwash," he said.

But it wasn't hogwash. He knew good and well it wasn't.

He fought it out with himself that night behind the closed door of his study, hearing faintly the soft bustling in the kitchen as Janet cleared away from supper.

And the first fight was on the front of credibility. He had told the man he believed he was an alien and there was evidence that he could not ignore.

Yet it seemed so incredible, all of it, every bit of it, that it was hard to swal-low.

And the hardest thing of all was that this alien, whoever he might be, had come, of all the doctors in the world, to Dr. Jason Kelly, a little one horse doctor in a little one horse town.

He debated whether it might be a hoax and decided that it wasn't, for the three digits on the hand and the other thing he'd seen would have been difficult to simulate. And the whole thing, as a hoax, would be so stupid and so cruel that it simply made no sense.

Besides, no one hated him enough to go to all the work. And even granting a hatred of appro-priate proportion, he doubted there was anyone in Millville imaginative enough to think of this.

So the only solid ground he had, he told himself, was to a.s.sume that the man had been really an alien and that the pads were bona fide.

And. if that was true, there was only one procedure: He must test the pads.

He rose from his chair and paced up and down the floor.

Martha Anderson, he told himself. Martha Anderson had cancer and her life was forfeit-there was nothing in man's world or knowledge that had a chance to save her. Surgery was madness, for she'd probably not survive it.And even if she did, her case was too advanced. The killer that she carried had already broken loose and was swarming through her body and there was no hope for her.

Yet he could not bring himself to do it, for she was Janet's closest friend and she was old and poor and every instinct in him screamed against his using her as a guinea pig.

Now if it were only old Con Gilbert-he could do a thing like that to Con. It would be no more than the old skinflint rightly had coming to him. But old Con was too mean to be really sick; despite all the complaining that he did, he was healthy as a hog.

No matter what the alien had said about no side effects, he told himself, one could not be sure. He had said they'd studied the metabolism of the human race and yet, on the face of it, it seemed impossible.

The answer, he knew, was right there any time he wanted it. It was tucked away back in his brain and he knew that it was there, but he pretended that it wasn't and he kept it tucked away and refused to haul it forth.

But after an hour or so of pacing up and down the room and of batting out his brains, he finally gave up and let the answer out.

He was quite calm when he rolled up his sleeve and opened up the box.

And he was a matter-of-fact physician when he lifted out the pad and slapped it on his arm.

But his hand was shaking when he rolled down the sleeve so Janet wouldn't see the pad and ask a lot of questions about what had happened to his arm.

Tomorrow all over the world outside Millville, people would line up before the clinic doors, with their sleeves rolled up and ready. The lines, most likely, would move at a steady clip, for there was little to it. Each person would pa.s.s before a doctor and the doctor would slap a pad onto his or her arm and the next person would step up.

All over the world, thought Doc, in every cranny of it, in every little village; none would be overlooked. Even the poor, he thought, for there would be no charge.

And one could put his finger on a certain date and say: "This was the day in history when disease came to an end." For the pads not only would kill the present ailments, but would guard against them in the future.

And every twenty years the great ships out of s.p.a.ce would come, carrying other cargoes of the pads and there would be another Vaccination Day. But not so many then-only the younger generation. For once a person had been vaccinated, there was no further need of it. Vaccinated once and you were set for life.

Doc tapped his foot quietly on the floor of the porch to keep the rockergoing. It was pleasant here, he thought. And tomorrow it would be pleasant in the entire world. Tomor-row the fear would have been largely filtered out of human life. After tomorrow, short of accident or violence, men could look forward confidently to living out their normal lifetime. And, more to the point, perhaps, completely healthy life-times.