He was alone in his office, and the automatic lock was adjusted to Dr. Henree's fingerprints only. He could feel some of his depression lifting. David Starr was on his way, suddenly and magically grown up, ready to receive his first assignment as a member of the Council. He felt almost as though his son were about to visit him. In a way, that was how it was. David Starr was his son: his and Augustus Henree's.

There had been three of them at first, himself and Gus Henree and Lawrence Starr. How he remembered Lawrence Starr! They had all three gone through school together, qualified for the Council together, done their first investigations together; and then Lawrence Starr had been promoted. It was to be expected; he was by far the most brilliant of the three.

So he had received a semi-permanent station on Venus, and that was the first time the three had not tackled a proposition together. He had gone with his wife and child. The wife was Barbara. Lovely Barbara Starr! Neither Henree nor himself had ever married, and for neither were there any girls to compete with Barbara in memory. When David was born, it was Uncle Gus and Uncle Hector, until he sometimes got confused and called his father Uncle Lawrence.

And then on the trip to Venus there was the pirate attack. It had been a total massacre. Pirate ships took virtually no prisoners in space, and more than a hundred human beings were dead before two hours had passed. Among them were Lawrence and Barbara.

Conway could remember the day, the exact minute, when the news had reached Science Tower. Patrol ships had shot out into space, tracing the pirates; they attacked the asteroid lairs in a fury that was completely unprecedented. Whether they caught the particular villains who had gutted the Venus-bound ship none could ever say, but the pirate power had been broken from that year on.

And the patrol ships found something else: a tiny lifeboat winding a precarious orbit between Venus and Earth, radiating its coldly automatic radio calls for help. Only a child was inside. A frightened, lonely four-year-old, who did not speak for hours except to say stoutly, "Mother said I wasn't to cry."

It was David Starr. His story, seen through childish eyes, was garbled, but interpretation was only too easy. Conway could still see what those last minutes within the gutted ship must have been like: Lawrence Starr, dying in the control room, with the outlaws forcing their way in; Barbara, a blast gun in her hand, desperately thrusting David into the lifeboat, trying to set the controls as best she could, rocketing it into space. And then?

She had a gun in her hand. As long as she could, she must have used it against the enemy, and when that could be no longer, against herself.

Conway ached to think of it. Ached, and once again wished they had allowed him to accompany the patrol ships so that with his own hands he might have helped to turn the asteroid caves into flaming oceans of atomic destruction. But members of the Council of Science, they said, were too valuable to risk in police actions, so he stayed home and read the news bulletins as they rolled out on the ticker tape of his telenews projector.

Between them he and Augustus Henree had adopted David Starr, bent their lives to erase those last horrible memories of space. They were both mother and father to him; they personally supervised his tutoring; they trained him with one thought in mind: to make him what Lawrence Starr had once been.

He had exceeded their expectations. In height he was Lawrence, reaching six feet, rangy and hard, with the cool nerves and quick muscles of an athlete and the sharp, clear brain of a first-class scientist. And beyond that there was something about his brown hair with the suggestion of a wave in it, in his level, wide-set brown eyes, in the trace of a cleft in his chin which vanished when he smiled, that was reminiscent of Barbara.

He had raced through his Academy days leaving a trail of sparks and the dead ash of previous records both on the playing fields and in the classrooms.

Conway had been perturbed. "It's not natural, Gus. He's outdoing his father."

And Henree, who didn't believe in unnecessary speech, had puffed at his pipe and smiled proudly.

"I hate to say this," Conway had continued, "because you'll laugh at me, but there's something not quite normal in it. Remember that the child was stranded in space for two days with just a thin lifeboat hull between himself and solar radiation. He was only seventy million miles from the sun during a period of sunspot maximum."

"All you're saying," said Henree, "is that David should have been burnt to death."

"Well, I don't know," mumbled Conway. "The effect of radiation on living tissue, on human living tissue, has its mysteries."

"Well, naturally. It's not a field in which experimentation is very feasible."

David had finished college with the highest average on record. He had managed to do original work in biophysics on the graduate level. He was the youngest man ever to be accorded full membership in the Council of Science.

To Conway there had been a loss in all this. Four years earlier he had been elected Chief Counselor. It was an honor he would have given his life for, yet he knew that had Lawrence Starr lived, the election would have gone in a worthier direction.

And he had lost all but occasional contact with young David Starr, for to be Chief Counselor meant that one had no life other than the beetling problems of all the Galaxy. Even at graduation exercises he had seen David only from a distance. In the last four years he might have spoken to him four times.

So Ms heart beat high when he heard the door open. He turned, walking rapidly to meet them as they walked in.

"Gus old man." He held out his hand, wrung the other's. "And David boy!"

An hour passed. It was true night before they could stop speaking of themselves and turn to the universe.

It was David who broke out. He said, "I saw my first poisoning today, Uncle Hector. I knew enough to prevent panic. I wish I knew enough to prevent poisoning."

Conway said soberly, "No one knows that much. I suppose, Gus, it was a Martian product again."

"No way of telling, Hector. But a marplum was involved."

"Suppose," said David Starr, "you let me know anything I'm allowed to know about this."

"It's remarkably simple," said Conway. "Horribly simple. In the last four months something like two hundred people have died immediately after eating some Mars-grown product. It's no known poison, the symptoms are those of no known disease. There is a rapid and complete paralysis of the nerves controlling the diaphragm and the muscles of the chest. It amounts to a paralysis of the lungs, which is fatal in five minutes.

"It goes deeper than that too. In the few cases where we've caught the victims in time, we've tried artificial respiration, as you did, and even iron lungs. They still died in five minutes. The heart is affected as well. Autopsies show us nothing except nerve degeneration that must have been unbelievably rapid."

"What about the food that poisoned them?" asked David.

"Dead end," said Conway. "There is always time for the poisoned item or portion to be completely consumed. Other specimens of the same sort at the table or in the kitchen are harmless. We've fed them to animals and even to human volunteers. The stomach contents of the dead men have yielded uncertain results."

"Then how do you know it's food poisoning at all?"

"Because the coincidence of death after eating a Martian product time after time, without known exception, is more than coincidence."

David said thoughtfully, "And it isn't contagious, obviously."

"No. Thank the stars for that. Even so, it's bad enough. So far we've kept this as quiet as we can, with full co-operation from the Planetary Police. Two hundred deaths in four months over the population of all Earth is still a manageable phenomenon, but the rate may increase. And if the people of Earth become aware that any mouthful of Martian food might be their last, the consequences could be horrible. Even though we were to point out that the death rate is only fifty per month out of a population of five billions, each person would think himself certain to be one of those fifty."

"Yes," said David, "and that would mean that the market for Martian food imports would fall through the floor. It would be too bad for the Martian Farming Syndicates."

"That!" Conway shrugged his shoulders, thrusting aside the problem of the Farming Syndicates as something of no moment. "Do you see nothing else?"

"I see that Earth's own agriculture can't support five billion people."

"That's it exactly. We can't do without food from the colonial planets. There would be starvation on Earth in sk weeks. Yet if the people are afraid of Martian food, there will be no preventing that, and I don't know how long it can be staved off. Each new death is a new crisis. Will this be the one that the tele-news will get hold of? Will the truth come out now? And there's Gus's theory on top of everything."

Dr. Henree sat back, tamping tobacco gently into Ms pipe. "I feel sure, David, that this epidemic of food poisoning is not a natural phenomenon. It is too widespread. It strikes one day in Bengal, the next day in New York, the day after in Zanzibar. There must be intelligence behind it."

"I tell you-" began Conway.

"Let him go on, Uncle Hector," urged David.

"If any group were seeking to control Earth, what better move could they make than to strike at our weakest point, our food supply? Earth is the most populous planet in all the Galaxy. It should be, since it is mankind's original home. But that very fact makes us the weakest world, in a sense, since we're not self-supporting. Our breadbasket is in the sky: on Mars; on Ganymede; on Europa. If you cut the imports in any manner, either by pirate action or by the much more subtle system being used now, we are quickly helpless. That is all."

"But," said David, "if that were the case, wouldn't the responsible group communicate with the government, if only to give an ultimatum?"

"It would seem so, but they may be waiting their time; waiting for ripeness. Or they may be dealing with the farmers of Mars directly. The colonists have minds of their own, mistrust Earth, and, in fact, if they see their livelihood threatened, may throw in with these criminals altogether. Maybe even," he puffed strenuously, "they themselves are____________________ But I'll make no accusations."

"And my part," said David. "What is it yqu would have me do?"

"Let me tell him," said Conway. "David, we want you to go to Central Laboratories on the Moon. You will be part of the research team investigating the problem. At this moment they are receiving samples of every shipment of food leaving Mars. We are bound to come across some poisoned item. Half of all items are fed to rats; the remaining portions of any fatal pieces are analyzed by all the means at our disposal."

"I see. And if Uncle Gus is right, I suppose you have another team on Mars?"

"Very experienced men. But meanwhile, will you be ready to leave for the Moon tomorrow night?"

"Certainly. But if that's the case, may I leave now to get ready?"

"Of course."

"And would there be any objection to my using my own ship?" "Not at all.''

The two scientists, alone in the room, stared down at the fairy-tale lights of the city for a long time before either spoke.

Finally Conway said, "How like Lawrence he is! But he's still so young. It will be dangerous."

Henree said, "You really think it will work?"

"Certainly!" Conway laughed. "You heard his last question about Mars. He has no intention of going to the Moon. I know him that well. And it's the best way to protect him. The official records will say he is going to the Moon; the men at Central Laboratories are instructed to report his arrival. When he does reach Mars, there will be no reason for your conspirators, if they exist, to take him for a member of the Council, and of course he will maintain an incognito because he will be busy fooling us, he thinks."

Conway added, "He's brilliant. He may be able to do something the rest of us could not do. Fortunately, he's still young and can be maneuvered. In a few years that will be impossible. He would see through us."

Conway's communicator tinkled gently. He flipped it open. "What is it?"

"Personal communication for you, sir."

"For me? Transmit it." He looked wildly at Henree. "It can't be from the conspirators you babble about."

"Open it and see," suggested Henree.

Conway sliced the envelope open. For a moment he stared. Then he laughed a bit wildly, tossed the open sheet to Henree, and slumped back in his chair.

Henree picked it up. There were only two scrawled lines which read, "Have it your way! Mars it is." It was signed, "David."

Henree roared with laughter. "You maneuvered him all right."

And Conway could not help but join.