"Oh. That's right -- you agents do that. Got too much of that dense android muscle in your brains." He grimaced. "What I meant was that this forest has never been touched by man. So it's not Earth -- not our Earth. And it's a high rainfall district, so it's not the desert world -- not this place, not this millennium, anyway. Look at the size of that pine!"

"The aperture does not necessarily lead to the same geographic spot on the alternate," she reminded him. "Each alternate seems to differ in time from the others, so it could differ in s.p.a.ce, too, since the globe is moving. For instance, we're in day here instead of night, so we must be elsewhere on the globe. There was vegetation on other parts of what you call the desert world."

"That's what I said. But no trees like this. Those machines ate wood, too. They'd have sawed into this long ago -- and they haven't."

He was right. Her perceptions showed a slightly differing chemical composition of this world's atmosphere. Though it would be foolish to judge an entire world by one view of a tiny fraction of it, it was a new alternate. The changes were minor but significant.

"I am not surprised," she admitted. "My aperture projector is set for Paleo -- but we did not start from the desert world. That sparkle-cloud moved us to an unspecified alternate, so we're out of phase."

"Yeah -- like taking the wrong bus."

That was hardly precise, and she was surprised he thought in terms of such an ancient vehicle, but it would do. "It may be a long, hard search for home."

"Your home, maybe. I'd settle for Paleo. Or Nacre."

"Nacre is part of the Earth-alternate. So you'd have to -- "

"But we can get back to the city-world all right? We're not lost from there?"

"Yes -- in just under three hours. We're in phase for that. But we shall have to be standing right on this spot, or we'll miss it."

"Well, let's not waste the time!" he exclaimed. "This is beautiful! Finest softwood forest I ever saw!"

She laughed. "By all means, look at the trees. But how can you be sure this isn't Paleo? Plenty of virgin softwood there!" She knew this wasn't Paleo, but was interested in his reasoning.

"Not the same. These are modern pines. See, the needles are different. Trees evolve, you know, same as animals do. This white pine, now -- actually, it's different from Earth white pine, in little ways -- "

She raised her hands in mock surrender. He was not pretending; at this moment, the forest really did interest him more than she did, and he knew more than she in this area of botany. Agents had an excellent general education, but they could not be experts in every field.

Meanwhile, the social environment had changed as well as the physical one. Just as s.e.x was relatively attractive to this country man when he was confined to the city, this challenging new -- rather, old -- forest was more attractive yet.

Which was not quite what she had antic.i.p.ated. There were always unexpected wrinkles appearing in normals! Agents, in pleasant contrast, were completely predictable -- to other agents. They were designed to be that way.

Pleasant contrast? It actually made for a certain tedium, she realized, when the mission stretched out longer than a few hours or days. In some things, predictability was less than ideal.

Watch yourself, she thought then. She was beginning to suffer from an overload of experience, and she had no dream mechanism to restore her mind to its prior equilibrium. It was inevitably shaping her into more of an individual than the computer could readily tolerate. If this went too far, her report would be suspect, even useless. The general rule was that an agent's mission should not continue longer than ten days because of that deterioration of reliability. She had already been nineteen days, and the end was not in sight.

She shuddered. How good it would be to return to computer central to be reset -- and how awful to remain out so long she lost her affinity with her series, TA!

Veg was moving among the trees, tapping the trunks, looking at needles. This was his element! He suffered no pangs of dawning ident.i.ty!

There were, it seemed, plenty of untouched worlds available for man's expansion. Earth's population and resources problem would be solved -- just as soon as she got back.

She would have to return, try another setting, and begin a survey of alternate-worlds. It would be too c.u.mbersome to step through every time. She would fashion a spot sensor that used very little power in projection because of its small ma.s.s. By bouncing it through and back like a tennis ball, she could check a dozen worlds in an hour, the only delay being the adjustment of the projector settings between uses.

She would not need Veg, after all. Not until she located familiar territory.

Three hours. She could sleep, for she had perfect timing and would wake when the return aperture was due. But first she would make a spot survey of this locale, for it might turn out to be the most suitable one yet discovered for exploitation. Earthlike, modern, no dinosaurs.

She lifted her hands, caught hold of a dead spoke on the huge pine, and hauled herself up. The trunk was a good six feet in diameter at the base, and the top was out of sight. She climbed rapidly, wriggling between the branches as they became smaller and more closely set. She was getting dirty, but that didn't matter. She really should have adjusted the seductive design of her outfit; trees were not much for that sort of thing, and her clothing inhibited progress. A few welts or scratches on the visible surfaces of her b.r.e.a.s.t.s would not bother her but could well turn off Veg -- and she just might need him.

The trunk thinned alarmingly at the top and swayed in the stiffening wind. At an elevation of two hundred feet she halted, looking about. There were a number of tall trees, some reaching to two hundred and fifty feet. White pine, when allowed to grow, was one of the tallest trees, comparable to the Douglas fir and young redwood. Veg would know all about that! But now these tall trees interfered with her vision, so that all she could see was more forest. She had wasted her time. No doubt Veg could have told her that, too!

She descended, to find him waiting for her, looking up. How like a man! She hardly needed to make an effort to show off her wares; he knew how to find them for himself. Tree-climbing skirt!

"No good climbing," he remarked. "That's boy-scout lore -- useless in a real forest. All you see is -- "

"More trees," she finished for him.

"I had a better view from the ground."

"Thank you."

"Found something else."

Now she read the signs in him: He was excited, and not merely by his nether-view of her thighs as she came down the tree. He knew that what he had to tell her would affect her profoundly.

Tamme paused, trying to ascertain what it was before he told her. It was not a threat, not a joke. Not a human settlement. What, then?

"Can't tell, can you!" he said, pleased. "Come on, then."

He showed the way to a small forest glade, a clearing made by a fallen giant tree and not yet grown in. The ma.s.sive trunk, eight feet thick, lay rotting on the ground. And near its sundered stump --

"An aperture projector!" she exclaimed, amazed.

"Thought you'd be surprised. Guess we weren't the first here, after all."

Tamme's mind was racing. There was no way that such a device could be here -- except as a relic of human visitation. Agent visitation, for this was an agent model, similar to hers. But not identical -- not quite.

"Some alternate-world agent has pa.s.sed this way," she said. "And not long ago. Within five days."

"Because the brush has not grown up around it," Veg said. "That's what I figured. Can't be yours, can it?"

"No." The implications were staggering. If an alternate-world agent had come here, then Earth was not alone. There could be millions of highly developed human societies possessing the secret of aperture travel, competing for unspoiled worlds. What would she do, if she encountered one of those foreign agents, as highly trained as she, as dedicated to his world as she was to Earth?

By blind luck she had learned of the other agent first. Before he learned of her.

This was likely to be the mission of her life -- and the fight of Earth's survival.

She had an immediate choice: Return to the surrealist city and commence her survey of alternates, hoping to discover in the process the route home. Or take a more chancy initiative by going after the competing agent and attempting to kill him before he could make his report to his world.

Each alternative was rife with bewildering complexities. She was trained to make quick decisions -- but never had the fate of Earth depended on her snap judgment, even potentially. So she sought an advisory opinion. "Veg -- if you came across the spoor of a hungry tiger, and you knew it was going to be him or you -- what would you do? Follow the trail, or go home for help?"

Veg squinted at her. "Depends how close home is, and how I am armed. But probably I'd go home. I don't like killing."

She had posed the wrong question -- another indication of her need for caution. An agent should not make elementary mistakes! Naturally the vegetarian would avoid a quarrel with an animal. "Suppose it was the track of a man as strong and as smart as you -- but an enemy who would kill you if you didn't kill him first?"

"Then I'd sure go home! I'm not going out looking for any death match!"