He compromised. “Look, pal,” he said, “I’m going to ask you to do some hard thinking and then you can go back to your boss.”

The “finger” nodded its head stiffly, but did not exert its limited brain-power on speech.

“Now on four occasions recently,” Powell said, “your boss deviated from brain-scheme. Do you remember those occasions?”

“Yes, sir.”

Donovan growled angrily, “He remembers. I tell you there is something very sinister—”

“Oh, go bash your skull. Of course, the ‘finger’ remembers. There is nothing wrong with him.” Powell turned back to the robot, “What were you doing each time… I mean the whole group.”

The “finger” had a curious air of reciting by rote, as if he answered questions by the mechanical pressure of his brain pan, but without any enthusiasm whatever.

He said, “The first time we were at work on a difficult outcropping in Tunnel 17, Level B. The second time we were buttressing the roof against a possible cave-in. The third time we were preparing accurate blasts in order to tunnel farther without breaking into a subterranean fissure. The fourth time was just after a minor cave-in.”

“What happened at these times?”

“It is difficult to describe. An order would be issued, but before we could receive and interpret it, a new order came to march in queer formation.”

Powell snapped out, “Why?”

“I don’t know.”

Donovan broke in tensely, “What was the first order… the one that was superseded by the marching directions?”

“I don’t know. I sensed that an order was sent, but there was never time to receive it.”

“Could you tell us anything about it? Was it the same order each time?”

The “finger” shook his head unhappily, “I don’t know.”

Powell leaned back, “All right, get back to your boss.”

The “finger” left, with visible relief.

Donovan said, “Well, we accomplished a lot that time. That was real sharp dialogue all the way through. Listen, Dave and that imbecile ‘finger’ are both holding out on us. There is too much they don’t know and don’t remember. We’ve got to stop trusting them, Greg.”

Powell brushed his mustache the wrong way, “So help me, Mike, another fool remark out of you, and I’ll take away your rattle and teething ring.”

“All right. You’re the genius of the team. I’m just a poor sucker. Where do we stand?”

“Right behind the eight ball. I tried to work it backward through the ‘finger,’ and couldn’t. So we’ve got to work it forward.”

“A great man,” marveled Donovan. “How simple that makes it. Now translate that into English, Master.”

“Translating it into baby talk would suit you better. I mean that we’ve got to find out what order it is that Dave gives just before everything goes black. It would be the key to the business.”

“And how do you expect to do that? We can’t get close to him because nothing will go wrong as long as we are there. We can’t catch the orders by radio because they are transmitted via this positronic field. That eliminates the close-range and the long-range method, leaving us a neat, cozy zero.”