"Perfectly." Lucky Starr moved up to Dr. Peverale's desk, sat down on one corner of it, and faced the assemblage. "Dr. Peverale will bear me out on that, I'm sure, when I've explained the reasoning."

"I'll bear you out? No fear of that, I assure you," huffed the old astronomer, his face set in an attitude of bitter disapproval. "It is scarcely worth discussing... By the way, we'll have to place Cook under arrest." He half rose.

Lucky urged him gently back into his seat. "It's all right, sir. Bigman will make sure that Cook will remain under control."

"I won't make any trouble," said the despairing Cook in a muffled tone. Bigman pulled his armchair close to Cook's nevertheless.

Lucky said, "Think back, Dr. Peverale, on the night of the banquet and of your own words concerning the Sirian robots... By the way, Dr. Peverale, you've known for a long time there was a robot on the planet, haven't you?"

The astronomer said uneasily, "What do you mean?"

"Dr. Mindes came to you with stories of having sighted moving manlike figures in what seemed like metal space-suits who also seemed to endure solar radiation better than one would expect humans to."

"I certainly did," interposed Mindes, "and I should have known I was seeing a robot."

"You didn't have the experience with robots that Dr. Peverale did," said Lucky. He turned to the old astronomer again. "I'm sure that you suspected the existence of Sirian-designed robots on the planet as soon as Mindes reported what he had seen. His description fit them perfectly."

The astronomer nodded slowly.

"I, myself," Lucky went on, "did not suspect robots when Mindes told me his story any more than he himself did. After the banquet, however, when, Dr. Peverale, you discussed Sirius and its robots, the thought occurred to me very forcefully that here was the explanation. You must have thought so too."

Dr. Peverale nodded slowly again. He said, "I realized that we ourselves could do nothing against a Sirian incursion. That is why I discouraged Mindes."

(Mindes turned pale at this point and muttered savagely to himself.)

Lucky said, "You never reported to the Council of Science?"

Dr. Peverale hesitated. "I was afraid they wouldn't believe me and that I would only succeed in getting myself replaced. Frankly, I didn't know what to do. It was obvious that I could make no use of Urteil. He was interested only in his own plans. When you came, Starr," his voice grew deeper, more flowing, "I felt I might have an ally at last, and for the first time I felt able to talk about Sirius, its dangers, and its robots."

"Yes," said Lucky, "and do you remember how you described the Sirian affection for their robots? You used the word 'love.' You said the Sirians pampered their robots; they loved them; nothing was too good for them. You said they would regard a robot as worth a hundred Earthmen."

"Of course," said Dr. Peverale. "That's true."

"Then if they loved their robots so much, would they send one of them to Mercury, uninsulated, un-adapted to Solar radiation? Would they condemn one of their robots to a slow, torturing death by the Sun?"

Dr. Peverale fell silent, his lower lip trembling.

Lucky said, "I, myself, could scarcely think of blasting the robot even though it endangered my life, and I am no Sirian. Could a Sirian have been so cruel to a robot, then?"

"The importance of the mission... " began Dr.

Peverale.

"Granted," said Lucky. "I don't say a Sirian wouldn't send a robot to Mercury for purposes of sabotage, but, Great Galaxy, they would have insulated its brain first. Even leaving their love for robots out of account, it's only good sense. They could get more service out of it."

There was a murmur of approval and agreement from the assemblage.

"But," stammered Dr. Peverale, "if not the Sirians then who... "

"Well," said Lucky, "let's see what leads we have. Number one. Twice Mindes spotted the robot, and twice it vanished when Mindes tried to draw close. The robot later informed me that it had been instructed to avoid people. Obviously, it had been warned that Mindes was out searching for the saboteur. Obviously, too, it must have been warned by someone inside the Dome. It wasn't warned against me, because I announced that I was going into the mines.

"Lead number two. As the robot lay dying, I asked once more who had given it its instructions. It could only say, 'Er-er... ' Then its radio blanked out, but its mouth moved as though it were making two syllables."

Bigman shouted suddenly, his pale red hair standing on end with passion, "Urteil! The robot was trying to say Urteil! That filthy cobber was the saboteur all the time. It fits in! It fits... "

"Maybe," said Lucky, "maybe! We'll see. It struck me as a possibility that the robot was trying to say, 'Earthman.'"

"And maybe," said Peverale dryly, "it was only a vague sound made by a dying robot and it meant nothing at all."

"Maybe," agreed Lucky. "But now we come to lead number three and it is instantly conclusive. That is this: The robot was of Sirian manufacture, and what human here at the Dome could possibly have had a chance to gain possession of a Sirian robot? Have any of us been on the Sirian planets?"

Dr. Peverale's eyes narrowed. "I have."

"Exactly," said Lucky Starr, "and no one else. That's your answer."

Mad confusion followed and Lucky called for silence. His voice was authoritative and his face stern. "As a Councilman of Science," he said, "I declare this observatory to be in my charge from this moment on. Dr. Peverale is replaced as director. I have been in communication with Council Headquarters on Earth, and a ship is on its way now. Appropriate action will be taken."

"I demand to be heard," cried Dr. Peverale.

"You will be," said Lucky, "but first listen to the case against you. You are the only man here who had the opportunity to steal a Sirian robot. Dr. Cook told us that you were awarded a robot for personal service during your stay on Sirius. Is that correct?"

"Yes, but... "

"You directed him into your own ship when you were through with him. Somehow you managed to evade the Sirians. Probably they never dreamed anyone could commit so horrible a crime, to them, as robot-stealing. They took no precautions against it for that reason, perhaps.

"What's more, it makes sense to suppose the robot was trying to say, 'Earthman' when I asked him who had given it instructions. You were the one Earthman on Sirius. You would be spoken of as 'Earthman' when the robot was first placed in your service, probably. It would think of you as 'Earthman.'

"Finally, who would know better when anyone might be exploring the Sun-side? Who would better inform the robot by radio when it might be safe and when it ought to go into hiding?"

"I deny everything," said Dr. Peverale tightly.

"There's no point in denying it," said Lucky. "If you insist on your innocence, the Council will have to send to Sirius for information. The robot gave me its serial number as RL-726. If the Sirian authorities say that the robot assigned to you during your stay on Skius was RL-726 and that it disappeared about the time you left Sirius, that will condemn you.

"Furthermore, your crime of robot-stealing was committed on Sirius, and because we have an extradi-' tion treaty with the Sirian planets we may be forced to release you into their custody. I would advise you, Dr. Peverale, to confess and let Earth's justice take its course, rather than to maintain innocence and risk what Sirius might do for your crime of having stolen one of their beloved robots and tortured it to death."

Dr. Peverale stared pitifully at the assemblage with unseeing eyes. Slowly, joint by joint, he collapsed and dropped to the floor.

Dr. Gardoma rushed to his side and felt for his heart. "He's alive," he said, "but I think he'd better be moved to bed."

Two hours later, with Dr. Gardoma and Lucky Starr at his bedside and with Council Headquarters in sub-etheric contact, Dr. Lance Peverale dictated his confession.

With Mercury falling rapidly behind and the sure knowledge that Council emissaries now had the situation in hand, relieving him of any feeling of responsibility, Lucky still felt tension. His expression was brooding and thoughtful.

Bigman, face puckered anxiously, said, "What's the matter, Lucky?"

"I'm sorry for old Peverale," said Lucky. "He meant well in his way. The Sirians are a danger, if not quite as immediate as he thought."

"The Council wouldn't have turned him over to Sirius, would it?"

"Probably not, but his fears of Sirius were sufficiently great to force his confession. It was a cruel trick, but necessary. However patriotic his motives, he had been forced into attempted murder. Cook, too, was goaded into his crime, yet it was none the less a crime, however little we think of Urteil."

Bigman said, "What did the old guy have against Project Light anyway, Lucky?"

"Peverale made that clear at the banquet," said Lucky grimly. "Everything was made clear that night. You remember, he complained that Earth was weakening itself by depending on imported food and resources. He said Project Light would make Earth dependent on space stations for the very manner in which it got its sunlight. He wanted Earth to be self-sufficient so that it could better resist the Sirian danger.

"In his slightly unbalanced mind, he must have thought he would help that self-sufficiency along by trying to sabotage Project Light. Perhaps he originally brought back the robot just as a dramatic demonstration of Sirian power. Finding Project Light in progress when he returned, he turned the robot into a saboteur instead.

"When Urteil arrived he must have been afraid at first that Urteil was going to investigate the Project Light affair and expose him. So he planted a slashed inso-suit in Urteil's room, but Urteil spotted it. Maybe Urteil really believed Mindes had been responsible."

Bigman said, "Sure, come to think of it. The first time we met the old guy he wouldn't even talk about Urteil, he was so mad about him."

"Exactly," said Lucky, "and there was no obvious reason why that should be, as in Mindes's case, for instance. I thought there might be some reason I knew nothing about."

"Is that what put you on to him first, Lucky?" "No, it was something else. It was the slashed inso-suit in our own room. The man with the best opportunity to do that was obviously Peverale himself. He also would be in the best position to dispose of the suit after it had killed its man. He best knew our assigned room, and he could assign an inso-suit too. What bothered me, though, was the motive? Why should he want to kill me?

"My name apparently meant nothing to Mm. He asked if I were a sub-temporal engineer like Mindes the first time we met. Now Mindes had recognized my name and tried to get me to help him. Dr. Gardoma had heard of me in connection with the poisonings on Mars. Urteil knew all about me, of course. I wondered if Dr. Peverale might not have heard of me too.

"There was Ceres, for instance, where you and I stayed a while during the battle against the pirates. The largest observatory in the System is there. Might not Dr. Peverale have been there then? I asked him that, and he denied having met me there. He admitted that he visited Ceres, and Cook later told us the old man visited Ceres frequently. Peverale went on to explain, without any prompting from me, that he had been sick in bed during the pirate raid, and Cook later backed that statement. That was the giveaway. In his anxiety, Peverale had talked too much." The little Martian stared. "I don't get that." "It's simple. If Peverale had been on Ceres a number of times, how was it he felt it necessary to alibi that particular time when the pirates had attacked?

Why that time and not another? Obviously, he knew on which occasion I had been on Ceres and was trying to alibi that one. Obviously, again, he knew who I was.

"If he knew me, why should he try to kill me, and Urteil too? Both of us suffered from slashed inso-suits, you know. We were both investigators. What was it Peverale feared?

"Then he began to talk about Sirians and robots at the banquet table, and things began to drop into place. Mindes's story suddenly made sense, and I knew at once that the only ones who could have brought a robot to Mercury were either Sirians or Dr. Peverale. To me it seemed that Peverale was the answer, that he was talking about Sirians now as a kind of insurance. If the robot were found and the sabotage stopped, it would serve as a smoke screen to hide his own part and, furthermore, it would make good anti-Sirian propaganda.

"I needed proof. Otherwise, Senator Swenson would shout we were setting up a smoke screen to cover the Council's own incompetence and extravagance. I needed good proof. With Urteil right on the ground, I dared not talk about the matter to anyone, Bigman, not even to you."

Bigman groaned in disgust. "When are you going to trust me, Lucky?"

"When I can count on you to avoid tricks like rough-and-tumbles with men twice your size," said Lucky with a smile that robbed the statement of some of its sting. "Anyway, I set out to capture the robot on the Sun-side and use him as evidence. That failed and I was forced to work a confession out of Peverale."

Lucky shook his head.

Bigman said, "What about Swenson now?"

"It's a draw, I think," said Lucky. "He can't do much with Urteil's death, since we can use Dr. Cook as a witness to show some of Urteil's dirty tactics. We can't do much against him, either, since the two top men at the Mercurian Observatory have had to be relieved of duty for felonies. It's a standoff."

"Sands of Mars!" moaned Bigman, "We'll have that cobber on our necks later on then."

But Lucky shook his head. "No, Senator Swenson is not a real cause for worry. He's ruthless and dangerous, but for that very reason he keeps the Council on its toes, keeps us from getting flabby.

"Besides," he added thoughtfully, "the Council of Science needs its critics, just as Congress and the government do. If ever the Council began to consider itself above criticism, then the time might come when it would establish a dictatorship over the Earth, and certainly I wouldn't want that to happen."

"Well, maybe," said Bigman, unsatisfied, "but I don't like that Swenson."

Lucky laughed and reached out to tousle the Martian's hair. "Nor I, but why worry about that now. Out there are the stars, and who knows where we'll be going next week, or why?"