"That would sound so much better without the 'my.' "

" 'In head?' "

She waggled a forefinger at him. " 'Dear.' "

"You are becoming positively flirtatious." Perhaps she was rebounding from Veg.

"Was Taler right on the ship?"

The ship. Again he looked into her eyes, remembering. The Earth government had not waited for the trio's report; it had sent four agents to Paleo to wrap it up, which agents had duly taken the normals prisoner and destroyed the dinosaur enclave. "Interesting," Taler had remarked while Tamme watched, amused. "Dr. Potter is even more enamored of Miss Hunt than is Mr. Smith. But Dr. Potter refuses to be influenced thereby."

"I suppose he was," Cal said.

She sighed as though she had antic.i.p.ated more of an answer. "There must be more to life than this."

He glanced at her again, uncertain which way she meant it. He elected to interpret it innocuously. "There is indeed. There are any number of game figures, each with its own history. Some patterns die out; others become stable like the square. Still others do tricks."

Now she was intrigued. "Let me try one!"

"By all means. Try this one." He made a tetromino, four dots:

Aquilon pounced on it. "There's an imaginary grid, right? The dots are really filling in squares and don't mesh the same on the bias?"

"That's right." She was quick, now that she had the idea; he liked that.

"If this is position one, then for position two we have to add one, two, three spots, and take away -- none." She made the new figure:

"Correct. How far can you follow it?"

She concentrated, tongue between her lips. At length, she had the full series. "It evolves into four blinkers. Here's the series." She marked off the numbers of the steps in elegant brackets so as the avoid the use of confusing periods.

[1] [2] [3] [4] [5] [6] [7].

[8] [9] [10] [11].

"Very good. That's 'Traffic Lights.' "

"Fascinating! They really work, too! But still, I don't see the relevance to -- "

"Try this one," he suggested, setting down a new pattern: "That's the 'R Pentomino.' "

"That's similar to the one I just did. You've just tilted it sideways, which makes no topological difference, and added one dot."

"Try it," he repeated.

She tried it, humoring him. But soon it was obvious that the solution was not a simple one. Her numbered patterns grew and changed, taking up more and more of the working area. The problem ceased to be merely intriguing; it became compulsive. Cal well understood this; he had been through it himself. She was oblivious to him now, her hair falling across her face in attractive disarray, teeth biting lips. "What a difference a dot makes!" she muttered.

Cal heard something. It was the hum of a traveling machine. The bait had finally been taken!

He moved quietly away from Aquilon, who did not miss him. He took his position near the light fountain. The next step was up to the mantas.

The machine hove into sight. It was exactly what Cal had hoped for: a multilensed optical specialist -- the kind fitted out to a.n.a.lyze a marginally defective light-pattern. One of the screens on it resembled an oscilloscope, and there seemed to be a television camera.

Excellent! This one must have been summoned from moth-balling, as light-surgery was no doubt necessary less frequently than mechanical repairs. This was an efficient city, which did not waste power and equipment.

The two mantas turned to concentrate on the machine. Cal knew they were directing their eye-beams at its lenses, attempting to send it intelligible information and usurp its control system. If anything could do it, the mantas could -- but only if the machine were sufficiently sophisticated.

It stopped, facing the mantas. Was the plan working?

Suddenly the machine whirled, breaking contact. Its intake lens spied Cal. The snout of a small tube swung about with dismaying authority.

Cal felt sudden apprehension. He had not expected physical danger to himself or Aquilon, and he was not prepared. His skin tightened; his eyes darted to the side to a.s.sess his best escape route or locate a suitable weapon. There was a nervous tremor in his legs.

He had played hide-and-seek with Tyrannosaurus, the largest predator dinosaur of them all. Was he now to lose his nerve before a mere repair robot?

Cal leaped aside as the beam of a laser scorched a pin-hole in the plastic wall behind the place he had just stood. He had seen the warm-up glow just in time. But now it was warmed up and would fire too fast for his reflexes. He scurried on as the laser projector reoriented.

His plan had malfunctioned -- and now the machine was on the attack. They were in for it!

The mantas tried to distract it, but the thing remained intent on Cal. Wherever he fled, it followed.

Aquilon, jolted out of her concentration, stepped forward directly into the range of the laser, raising her hand. Her chin was elevated, her hair flung back, her body taut yet beautiful in its arrested dynamism. For an instant she was a peremptory queen. "Stop!" she said to the machine.

It stopped.

Startled, Cal turned back. Had the machine really responded to a human voice -- or was it merely orienting on a new object? Aquilon's life depended on that distinction!

Aquilon herself was amazed. "I reacted automatically, foolishly," she said. "But now -- I wonder." She spoke to the machine again. "Follow me," she said, and began to walk down the path.

The machine stayed where it was, unmoving. Not even the laser tube wavered, though now it covered nothing.

"Wait," Cal murmured to her. "It begins to come clear. You gave that machine a pre-emptive directive."

"I told it to stop," she agreed. "I was alarmed. But if it understood and obeyed me then, why not now?"

"You changed the language," he said.

"I what?"

"The first time you addressed it, you used body language. Everything about you contributed to the message. You faced it without apparent fear, you raised your hand, you gave a brief, peremptory command."

"But I spoke English!"

"Irrelevant. No one could have mistaken your meaning." He put his hand under her arm, pulling her gently toward him. "Body language -- the way we move, touch, look -- the tension of our muscles, the rate of our pulse, our respiration -- the autonomic processes. The agents virtually read our minds through those involuntary signals."

"Yes," she said, seeing it. "Your hand on me -- that's speaking, too, more than your words."

He let go quickly. "Sorry. I just wanted you to understand -- "