"If she's yours," demanded Fargo, sounding angry, "what was she doing inside a hassock all these years? You didn't even know where she was. You didn't care for her one bit, and I do. I claim her. Oola, come to me."

Oola jumped down and stood between the Mentor and Fargo, looking anxiously from one to the other, her ears growing first longer and beaglelike, then shorter and tigerlike.

The Mentor's massive head turned to Jeff. "You were here intruding before. You refused scanning, and you would not help me. You will be scanned now, you and this other creature like you."

Fargo stepped between Jeff and the Mentor. "Now just a minute, sir. Not only are you wrong about the All-Purpose Pet, you are wrong about us. We mean no harm. We have come to find the origins of our own robot, part of whose mechanism may have come from Jamya…Norby, where are you?"

Norby was inside his barrel completely up against the computer. Only his feeler wire was extended and it touched the computer.

Jeff ran to him, "Norby? Are you all right? Answer me!" He bent to touch him and got an electric shock. "Fargo, something's wrong! Norby's tied in to the computer and I can't get him loose!"

"Release our robot, Mentor," said Fargo threateningly.

With that, the Mentor's eyes flashed red. His two right arms seized Fargo about the waist and held him up in the air.

"Monster!" shouted the Mentor. "You interrupted me at important work and I may never…I will not endure this! You will be scanned until everything you know and are becomes part of the computer and your body will be left an empty shell incapable of harming or disturbing me."

Fargo stopped struggling because nothing could break the Mentor's grip. Instead, he laughed, and at that Jeff shook his head. It was Fargo's up-and-at-'em laugh, and it never failed to create trouble.

Jeff stepped up close to the Mentor to try to reason with him, as Fargo had so carefully taught him to do all his life-and as Fargo so infrequently did himself.

It was too late. Still wearing the antigrav collar taken from the Grand Dragon, Fargo rose in the air, carrying the Mentor with him. They swung out into the main auditorium, zooming up into the thick darkness of the high-ceilinged room.

"Fargo, don't!" Jeff called, but Fargo was out of sight in the gloom and did not answer.

"Norby, come out of it. Help me! I can't antigrav without you."

"Meow?" Oola pressed against Jeff's leg and he patted her, absently. As he did so, he became aware of the thin, expandable collar around her neck.

"Oola, can you antigrav?"

"Rowrr?" Oola's fangs disappeared and she looked very much like a Terran housecat, purring against Jeff's leg.

There were terrible noises coming from the darkness overhead, and Jeff, feeling frantic about Fargo, picked up Oola. Holding her close to his chest, he bent his head to hers and thought, very hard, picturing a small cat going up in the air.

Oola meowed once more, and Jeff began to rise. Linking himself telepathically with a not-to-bright All-Purpose Pet that had saber-tooth ancestors was an interesting experience, but difficult to manage. They went up and down, and finally sailed upward-a bit too quickly-toward the Mentor.

The darkness began to separate into distinct shapes, and Jeff could see that the Mentor was still holding Fargo.

Fargo's eyes were shut, his jaw grimly set.

Jeff somehow guided Oola that way. "Don't hurt my brother, Mentor! If you want me to help you…"

Fargo opened one eye, "Shut up, kid. I'm under a strain, trying to do battle with this antiquated hulk, and I have no room to take care of you."

"Why don't you just threaten to let go of your antigrav?"

"Then I fall, too, don't I?"

"Just a little. Fall slowly and let him bang against the floor, then up, then down with another bang, and so on." Jeff had trouble getting the words out, so anxious was he that Fargo understand.

The Mentor understood. He made a sound like gears grinding horribly. "I will let you go, alien monster, if you get me down to the ground. Don't do as the other monster suggests. I am nearly dead and I will be quickly destroyed it there is hard contact with the ground."

Fargo looked at Jeff. Jeff looked at Fargo.

"Let's go down," said Jeff, "Nice and easy." Unfortunately, he didn't count on Oola's reaction. Without warning, she jumped from his arms to the Mentor's shoulder and Jeff found himself in midair without antigrav.

He cried, "Help! I'm falling!"

Fargo yelled, too, as he desperately dropped with the Mentor and tried to snatch at his falling brother.

Jeff was trying to shrink back from the rapidly approaching floor when he felt two hard hands grab him. They were not Fargo's, but the Mentor's. Jeff was hanging from the Mentor's left arms, facing Fargo, who was still wearing the antigrav collar, and was still clutched by the Mentor's two right arms.

Fargo cancelled the fall with such vigor that all three-four, counting Oola-shot upward again.

"Wow!" said Fargo, shaking his head to free his left ear from Oola's enthusiastic licking. "That was close!"

He slapped Jeff's arm and grinned. "Let's all go down slowly, now, and have a reasonable conversation about this. Haven't I always told you, Jeff, that logical argument is better than derring-do?"

"Sure," said Jeff. "You've always told me. What you don't do is show me." His feet reached the floor and the Mentor let go first of Jeff and then of Fargo.

The two brothers watched while the enormous robot, with Oola resting comfortably on his shoulder, clumped slowly back into the scanning room, where Norby still sat inside his barrel. The Mentor sat down and put his head in his hands.

"Suddenly, I'm sorry for him," said Fargo in Terran Basic. "He's such an old robot."

"I think he's Mentor First," said Jeff in Jamyn.

"Yes," said the Mentor, looking up. "How did you know that?"

"We came to see you, long ago, just after you had been activated to do your work here," said Jeff, gently. The Mentor First they'd met then had been so strong, so gleamingly new.

"Surely you could not be alive for so long; we were activated thirty thousand years ago. And I do not remember you," said the Mentor. He said this in Terran Basic.

"You have learned to speak our language!" said Jeff.

"Since you left two weeks ago, the computer analyzed your language and I have learned it-enough to know that you pity me. An alien such as yourself should not take the liberty of pitying me; it is not your place to do so. And yet-and yet I find it strangely comforting. Perhaps, now, you will help me remove this terrible fear I have."

"What is the fear?" Jeff asked softly.

"When you would not help, I scanned you, hoping the computer and I could find out how you got to Jamya." The Mentor's head hung lower, and his body seemed to quiver.

"What's the matter?" asked Fargo. "Are you afraid of us?"

"No, no. I am afraid of myself. I am so seriously out of order that, at times, I am not in a position of mental stability, and the moments-of insanity-have come more frequently. When my Pet came back to me so unexpectedly, I felt myself becoming sane once more, but I don't know how long that will last. If I become insane again, you must leave me here in the scanner. The computer is adjusted to deactivate me if I become too dangerous."

Jeff was horrified. Suddenly the thought of Mentor First as a villain seemed grotesque. He was a sad and suffering machine.

Jeff protested, "But you mustn't kill yourself."

"I must, if I cannot be cured. And I do not think a cure is possible. I am too old. All the other Mentors have died, and I am too much alone. Caring for the Jamyn by myself is more than I can manage and even my Pet has been away from me for too long. We have no means of entering hyperspace to refuel ourselves, you see. The Others wanted to isolate this planet, and they must have thought they would be back long before our enormous supply of fuel would be consumed, but they have not come back."