“Yes,” said Herbie, in tones barely heard.

“Hold on,” broke in Bogert angrily. “That’s not necessary true. You want to hear that, that’s all.”

“Don’t be a fool,” replied Calvin. “He certainly knows as much math as you and Lanning together, since he can read minds. Give him his chance.”

The mathematician subsided, and Calvin continued, “All right, then, Herbie, give! We’re waiting.” And in an aside, “Get pencils and paper, gentlemen.”

But Herbie remained silent, and there was triumph in the psychologist’s voice, “Why don’t you answer, Herbie?”

The robot blurted out suddenly, “I cannot. You know I cannot! Dr. Bogert and Dr. Lanning don’t want me to.”

“They want the solution.”

“But not from me.”

Lanning broke in, speaking slowly and distinctly, “Don’t be foolish, Herbie. We do want you to tell us.”

Bogert nodded curtly.

Herbie’s voice rose to wild heights, “What’s the use of saying that? Don’t you suppose that I can see past the superficial skin of your mind? Down below, you don’t want me to. I’m a machine, given the imitation of life only by virtue of the positronic interplay in my brain – which is man’s device. You can’t lose face to me without being hurt. That is deep in your mind and won’t be erased. I can’t give the solution.”

“We’ll leave,” said Dr. Lanning. “Tell Calvin.”

“That would make no difference,” cried Herbie, “since you would know anyway that it was I that was supplying the answer.”

Calvin resumed, “But you understand, Herbie, that despite that, Drs. Lanning and Bogert want that solution.”

“By their own efforts!” insisted Herbie.

“But they want it, and the fact that you have it and won’t give it hurts them. You see that, don’t you?”

“Yes! Yes!”

“And if you tell them that will hurt them, too”

“Yes! Yes!” Herbie was retreating slowly, and step-by-step Susan Calvin advanced. The two men watched in frozen bewilderment.

“You can’t tell them,” droned the psychologist slowly, “because that would hurt and you mustn’t hurt. But if you don’t tell them, you hurt, so you must tell them. And if you do, you will hurt and you mustn’t, so you can’t tell them; but if you don’t, you hurt, so you must; but if you do, you hurt, so you mustn’t; but if you don’t, you hurt, so you must; but if you do, you-”

Herbie was up against the wall, and here he dropped to his knees. “Stop!” he shrieked. “Close your mind! It is full of pain and frustration and hate! I didn’t mean it, I tell you! I tried to help! I told you what you wanted to hear. I had to!”

The psychologist paid no attention. “You must tell them, but if you do, you hurt, so you mustn’t; but if you don’t, you hurt, so you must; but-”

And Herbie screamed!

It was like the whistling of a piccolo many times magnified – shrill and shriller till it keened with the terror of a lost soul and filled the room with the piercingness of itself.

And when it died into nothingness, Herbie collapsed into a huddled heap of motionless metal.

Bogert’s face was bloodless, “He’s dead!”

“No!” Susan Calvin burst into body-racking gusts of wild laughter, “not dead – merely insane. I confronted him with the insoluble dilemma, and he broke down. You can scrap him now – because he’ll never speak again.”

Lanning was on his knees beside the thing that had been Herbie. His fingers touched the cold, unresponsive metal face and he shuddered. “You did that on purpose.” He rose and faced her, face contorted.

“What if I did? You can’t help it now.” And in a sudden access of bitterness, “He deserved it.”

The director seized the paralyzed, motionless Bogert by the wrist, “What’s the difference. Come, Peter.” He sighed, “A thinking robot of this type is worthless anyway.” His eyes were old and tired, and he repeated, “Come, Peter!”

It was minutes after the two scientists left that Dr. Susan Calvin regained part of her mental equilibrium. Slowly, her eyes turned to the living-dead Herbie and the tightness returned to her face. Long she stared while the triumph faded and the helpless frustration returned – and of all her turbulent thoughts only one infinitely bitter word passed her lips.

“Liar!”

It was one of Gregory Powell’s favorite platitudes that nothing was to be gained from excitement, so when Mike Donovan came leaping down the stairs toward him, red hair matted with perspiration, Powell frowned.

“What’s wrong?” he said. “Break a fingernail?”

“Yaaaah,” snarled Donovan, feverishly. “What have you been doing in the sublevels all day?” He took a deep breath and blurted out, “Speedy never returned.”

Powell’s eyes widened momentarily and he stopped on the stairs; then he recovered and resumed his upward steps. He didn’t speak until he reached the head of the flight, and then:

“You sent him after the selenium?”

“Yes.”

“And how long has he been out?”

“Five hours now.”

Silence! This was a devil of a situation. Here they were, on Mercury exactly twelve hours – and already up to the eyebrows in the worst sort of trouble. Mercury had long been the jinx world of the System, but this was drawing it rather strong – even for a jinx.

Powell said, “Start at the beginning, and let’s get this straight.”

They were in the radio room now – with its already subtly antiquated equipment, untouched for the ten years previous to their arrival. Even ten years, technologically speaking, meant so much. Compare Speedy with the type of robot they must have had back in 2005. But then, advances in robotics these days were tremendous. Powell touched a still gleaming metal surface gingerly. The air of disuse that touched everything about the room – and the entire Station – was infinitely depressing.

Donovan must have felt it. He began: “I tried to locate him by radio, but it was no go. Radio isn’t any good on the Mercury Sunside – not past two miles, anyway. That’s one of the reasons the First Expedition failed. And we can’t put up the ultrawave equipment for weeks yet -”

“Skip all that. What did you get?”

“I located the unorganized body signal in the short wave. It was no good for anything except his position. I kept track of him that way for two hours and plotted the results on the map.”

There was a yellowed square of parchment in his hip pocket – a relic of the unsuccessful First Expedition – and he slapped it down on the desk with vicious force, spreading it flat with the palm of his hand. Powell, hands clasped across his chest, watched it at long range.

Donovan’s pencil pointed nervously. “The red cross is the selenium pool. You marked it yourself.”

“Which one is it?” interrupted Powell. “There were three that MacDougal located for us before he left.”

“I sent Speedy to the nearest, naturally; seventeen miles away. But what difference does that make?” There was tension in his voice. “There are the penciled dots that mark Speedy’s position.”

And for the first time Powell’s artificial aplomb was shaken and his hands shot forward for the map.

“Are you serious? This is impossible.”

“There it is,” growled Donovan.

The little dots that marked the position formed a rough circle about the red cross of the selenium pool. And Powell’s fingers went to his brown mustache, the unfailing signal of anxiety.

Donovan added: “In the two hours I checked on him, he circled that damned pool four times. It seems likely to me that he’ll keep that up forever. Do you realize the position we’re in?”

Powell looked up shortly, and said nothing. Oh, yes, he realized the position they were in. It worked itself out as simply as a syllogism. The photocell banks that alone stood between the full power of Mercury’s monstrous sun and themselves were shot to hell.

The only thing that could save them was selenium. The only thing that could get the selenium was Speedy. If Speedy didn’t come back, no selenium. No selenium, no photocell banks. No photo-banks – well, death by slow broiling is one of the more unpleasant ways of being done in.