It was Cimon who worried Sheffield. He, the psychologist felt, must have argued the Captain into this and it was he who might insist on the extreme penalty. Sheffield was bitterly regretful of having punctured the man’s pathological vanity.

But what really puzzled Sheffield above all was Mark’s attitude. He was showing no signs of space-sickness or of unease of any kind. He listened to everything closely but seemed moved by nothing. He acted as though nothing mundane concerned him at the moment; as though certain information he himself held made everything else of no account.

The Captain banged his T-wedge “and said, “I guess we have it all. Facts all clear. No argument. We can finish this.”

Sheffield jumped up again. “Hold on. Aren’t we getting our turn?”

“Quiet,” ordered the Captain.

”You keep quiet.” Sheffield turned to the audience. “Listen, we haven’t had a chance to defend ourselves. We haven’t even had the right to cross-examine. Is that just?”

There was a murmur that buzzed up above the sound of the T-wedge.

Cimon said coldly, “What’s there to defend?”

“Maybe nothing,” shouted back Sheffield, “in which case what have you to lose by hearing us? Or are you afraid we have considerable to defend?”

Individual calls from the audience were sounding now. “Let him talk!”

Cimon shrugged. “Go ahead.”

The Captain said sullenly, “What do you want to do?”

Sheffield said, “Act as my own lawyer and call Mark Annuncio as witness.”

Mark stood up calmly enough. Sheffield turned his chair to face the audience and motioned him down again.

Sheffield decided there was no use in trying to imitate the courtroom dramas he had watched on the subether. Pompous questions on name and condition of past life would get nowhere. Better to be direct.

So he said, “Mark, did you know what would happen when you told the crew about the first expedition?”

“Yes, Dr. Sheffield.”

“Why did you do it then?”

“Because it was important that we all get away from Junior without losing a minute. Telling the crew the truth was the fastest way of getting us off the planet.”

Sheffield could feel the bad impression that answer made on the audience, but he could only follow his instinct. That, and his psychologist’s decision that only special knowledge could make Mark or any Mnemonic so calm in the face of adversity. After all, special knowledge was their business.

He said, “Why was it important to leave Junior, Mark?” Mark didn’t flinch. He looked straight at the watching scientists. ”Because I know what killed the first expedition, and it was only a question of time before it killed us. In fact, it may be too late already. We may be dying now. We may, every one of us, be dead men.”

Sheffield let the murmur from the audience well up and subside. Even the Captain seemed shocked into T-wedge immobility while Cimon’s smile grew quite faint.

For the moment, Sheffield was less concerned with Mark’s “knowledge,” whatever it was, than that he had acted independently on the basis of it. It had happened before. Mark had searched the ship’s log on the basis of a theory of his own. Sheffield felt pure chagrin at not having probed that tendency to the uttermost then and there.

So his next question, asked in a grim enough voice, was, “Why didn’t you consult me about this, Mark?”

Mark faltered a trifle. “You wouldn’t have believed me. It’s why I had to hit you to keep you from stopping me. None of them would have believed me. They all hated me.”

“What makes you think they hated you?”

“Well, you remember about Dr. Rodriguez.”

“That was quite a while ago. The others had no arguments with you.”

“I could tell the way Dr. Cimon looked at me. And Dr. Fawkes wanted to shoot me with a blaster.”

“What?” Sheffield whirled, forgetting in his own turn any formality due the trial “Say, Fawkes, did you try to shoot him?”

Fawkes stood up, face crimson, as all turned to look at him. He said, “I was out in the woods and he came sneaking up on me. I thought it was an animal and took precautions. When I saw it was he, I put the blaster away.”

Sheffield turned back to Mark. “Is that right?”

Mark turned sullen again. “Well-I asked Dr. Vernadsky to see some data he had collected and he told me not to publish it before he did. He tried to make out that I was dishonest.”

“For the love of Earth, I was only joking,” came a yell from the audience.

Sheffield said hurriedly, “Very well, Mark, you didn’t trust us and you felt you had to take action on your own. Now, Mark, let’s get to the point. What did you think killed the first settlers?”

Mark said, “It might have killed the explorer, Makoyama, too, for all I know except that he died in a crash two months and three days after reporting on Junior, so we’ll never know.”

“All right, but what is it you’re talking about?”

A hush fell over everyone.

Mark looked about and said, “The dust.”

There was general laughter, and Mark’s cheeks flamed.

Sheffield said, “What do you mean?”

“The dust! The dust in the air. It had beryllium in it. Ask Dr. Vernadsky.”

Vernadsky stood up and pushed his way forward. “What’s this?”

“Sure,” said Mark. “It was in the data you showed me. Beryllium was very high in the crust, so it must be in the dust in the air as well.”

Sheffield said, “What if beryllium is there? Let me ask the questions, Vernadsky. Please.”

“Beryllium poisoning, that’s what. If you breathe beryllium dust, non-healing granulomata, whatever they are, form in the lungs. Anyway, it gets hard to breathe and eventually you die.”

A new voice, quite agitated, joined the melee. “What are you talking about? You’re no physician.” It was Novee.

“I know that,” said Mark earnestly, “but I once read a very old book about poisons. It was so old it was printed on actual sheets of paper. The library had some and I went through them because it was such a novelty, you know.”

“All right,” said Novee. “What did you read? Can you tell me?”

Mark’s chin lifted. “I can quote it. Word for word. ‘A surprising variety of enzymatic reactions in the body are activated by any of a number of divalent metallic ions of similar ionic radius. Among these are magnesium, manganous, zinc, ferrous, cobaltous, and nickelous ions, as well as others. Against all of these, the beryllium ion, which has a similar charge and size, acts as an inhibitor. Beryllium therefore serves to derange a number of enzyme-catalyzed reactions. Since the lungs have, apparently, no way of excreting beryllium, diverse metabolic derangements causing serious illness and death can result from inhaling dust containing certain beryllium salts. Cases exist in which one known exposure has resulted in death. The onset of symptoms is insidious, being delayed sometimes for as long as three years after exposure. Prognosis is not good.’”

The Captain leaned forward in agitation. “What’s all this, Novee? Is what he’s saying making sense?”

Novee said, “I don’t know if he’s right or not, but there’s nothing absurd in what he’s saying.”

Sheffield said sharply, “You mean you don’t know if beryllium is poisonous or not.”

“No, I don’t,” said Novee. “I’ve never read anything about it. No case has ever come up.”

“Isn’t beryllium used for anything?” Sheffield turned to Vernadsky. “Is it?”

Vernadsky said in vast surprise, “No, it isn’t. Damn it, I can’t think of a single use. I tell you what, though. In the early days of atomic power, it was used in the primitive uranium piles as a neutron decelerator, along with other things like paraffin and graphite. I’m almost sure of that.”

“It isn’t used now, though?” asked Sheffield.

“No.”

An electronics man said quite suddenly, “I think beryllium-zinc coatings were used in the first fluorescent lights. I seem to recall a mention of that.”