Game theory is one of those computer technologies that used to be mathematics before there were computers. It's about anticipating what the other player would do in a particular situation, with the assumption that he wants to win as much as you do. "Win" in this case -- at least in the short term -- probably meant building a communication bridge between Lazir's expedition and humans, so the desired outcome was clearly win-win. What their long-term goals were was anybody's guess, but they seemed peaceful for now.

Alpha-beta pruning is a game-theoretic computer method for analyzing a game situation. It assumes that each player will maximize his own chance of winning. Therefore in guessing at the opponent's next move, the analysis disregards any moves that do not improve the chance of winning from the perspective of the side being considered. The reason is that the number of possible moves in any interesting game is astronomical -- Enoch smiled at the metaphor -- and cannot be computed in depth within the lifetime of the universe. Using computer technology as a metaphor for human activity is a common way for programmers to think, and Enoch was mentally doing some alpha-beta pruning on what might be going on inside Lazir's head. Surely Lazir was doing the same over Enoch. Chess players are penalized for taking too long to decide their next move, so they try to do as much of their planning on their opponent's clock as possible. This obviously wasn't chess, but both players, Enoch and Lazir, were mentally analyzing the situation.

Fact: Lazir was clearly in communication with the rest of his party in the spaceship. They were probably jabbering back and forth right now, even as they waited. They are probably engaged full-time analyzing everything going on, and feeding him advice. They were the ones who figured out he needed the voice-coder box, and called him back to get it.

Fact: Lazir's normal communication was not audio, at least not in the audible range of human hearing. If it were, Enoch would have heard them talking through the spacesuit. Perhaps not through the helmet, but the fabric of the rest of his suit did not seem likely to block sound.

Fact: They were clearly aware of and skilled in controlling radio waves in a variety of frequencies. Ship-to-Lazir communication had to be some kind of electromagnetic radiation (that is, radio), and it had to be a different frequency than what Enoch's computers were using for their local area network, and different from the cell frequencies of Enoch's phone.

Fact: Any radio frequency lower than microwaves spreads out all over and would be detected beyond their intended receiver, Lazir.

Fact: They obviously wanted a limited contact today. Otherwise they would have landed in a city, not out here in the desert.

Fact: Microwave radio (and higher) is line-of-sight only; it would be blocked by the hillock they were now standing on.

Therefore, Lazir probably understands that to go down the hill towards Enoch's house would cut him off from the rest of his party and the support they provide him. That's a problem.

There was also the strategic issue. Although their ship was on Enoch's property, on Enoch's earth, the hillock blocked them off from his house. From a military perspective, they controlled the local area on their side of the hill. If Enoch had a support team (did they know he was alone?) in his house, going over the hill would put Lazir in Enoch's area of control, and out of his own. Bullets and laser weapons don't shoot around corners and over hills. Guided missiles are for larger distances. How could they defend their advance party? If they wanted to. Enoch could only assume they had weapons trained on him at all times.

They broke the impasse. Enoch noticed some motion out of the corner of his eye, another little guy coming out of the plane, carrying some contraption on the end of a stick. He didn't come directly toward them, but rather headed for the high point of the hill some 15 yards away. The stick turned out to be a folded tripod, which he set up and anchored there on the crest, and then adjusted the instrument on it, and finally scurried back to the plane. It was obviously a microwave transponder, to reflect their communications over the hill and back.

It could also be a camera, or maybe even a weapon. Enoch thought he saw part of it rotate towards them, and then swivel toward the house, and then back to them.

Panic gripped Enoch for a moment, before he realized that if their intentions were hostile they would be out in force, not just one guy alone with Enoch. Even the second guy who came out with the transponder seemed afraid to stay out there in the open. Alpha-beta pruning.

Lazir now started down the hill with Enoch, apparently satisfied that he would still be in communication with the home ship. Was the instrument turning to track their progress down the hill? Enoch couldn't tell. He was more concerned with how to persuade Lazir to come inside the house.

"House," Enoch announced, pointing to it. "Water tower. Road." Lazir repeated each word.

"Radio," Enoch said, pointing to the transponder, then pointed to his laptop and repeated "radio," and again, pointing to the house. He then grabbed his cell phone and waved it around, and repeated "radio" again. He put the phone back and made a swooping gesture, pointing over the hill toward the plane now out of sight, and repeated the word. "Radio," he said again, swinging his finger to point to the transponder, and then again as he swung around to point to Lazir.

Lazir got it. "Radio," he said, pointing to the transponder. Then bringing his hand up to his helmet, repeated it. Then he pointed to the voice box, and repeated "radio."

Enoch was surprised. He had supposed the voice box was self-contained. Apparently there was a lot of processing going on back on the ship's computer to support the voice synthesis. Or maybe they were just recording everything. Probably both.

They came off the hill and Enoch could see the front door was still open. He decided to leave it that way. Closing the door with Lazir inside could be taken as aggressive. "Come," he said heading up the walk towards the door. "Lazir come."

Enoch went in, but Lazir hesitated again at the door. The transponder was still visible from the doorway, but Enoch could no longer see it from inside. If Lazir followed him inside, the transponder would not be visible to him. Would the transmissions penetrate the walls of the house? The computer net did, but it was probably a lower frequency, because it also went over the hill. Lazir stepped slowly inside, as if testing reception as he went. He seemed satisfied, and then followed Enoch into the living room.

"TeeVee," Enoch said, and turned it on manually. "Radio." Then he walked over to the chair and picked up the remote and repeated "radio." That was a lie, it's really infrared, but the idea is the same. He changed channels and turned it off then back on, and repeated "radio." Lazir didn't say anything. Maybe he was thinking. More likely he was communicating his experience back to his team on the plane. He reached for the remote and Enoch gave it to him. He seemed a little confused by all the buttons, so Enoch pointed to the channel-up and -down buttons ("up" and "Down") and read the channel numbers off the screen as they changed.

Lazir pressed the buttons but nothing happened, because he was pointing it the wrong direction. Without taking it away from him, Enoch pointed it toward the TV and said "try again." This time Lazir was able to make it work. He did that a couple times, then moved the remote a little away and tried again. It still worked. A little farther still worked, but when he pointed it beyond that, it stopped working. Lazir turned it around to look at the end. There was a little LED lens on the end, but Enoch could not tell if Lazir knew what he was seeing. Enoch pointed to it and said "infrared radio." Then he pointed it at the TV, but covered the end with his hand and pressed the button again. Nothing happened of course. Enoch went over to the TV and covered the receiver lens with his hand and said "try again." Lazir pointed the remote toward the TV and pressed the button. Nothing. Enoch removed his hand and Lazir tried again. It worked.

Enoch remembered he had a set-top box connected to his computer net. He set the laptop down on the coffee table, powered it up, and started up a video streaming program to capture the built-in web cam and send it to the TV. Then he reached for the remote and changed the video source to his net signal. "Radio," he announced. The TV showed Enoch's face.

He swivelled the laptop around to point it at Lazir. Lazir moved a little to see that he was live on the TV, then stopped. Enoch guessed he was communicating with the team. Enoch pointed to Lazir's helmet and said "radio." Lazir pointed to his own helmet and repeated "radio." Then the image on the TV broke up.

Enoch guessed they were trying to send their own image over the network, and the set-top box was mixing up the images. He shut down his laptop streaming, and the TV stabilized to a picture of -- he guessed it was the inside of their plane. The image swung around to a porthole, then through the window to the water tower looming over the hilltop, then back inside the plane. They were telling him that it was their transmission.

Enoch decided to try and bring up sound. He turned the streaming back on, and the TV picture scrambled again, then stabilized on his own transmission. He enabled the laptop microphone and started speaking. The feedback through the TV started howling, so he reduced the sound volume on the remote and pointed the laptop away from the TV. "One, two, three, four," he said. Then he pointed to Lazir and said "say something." Lazir didn't seem to understand. Enoch tapped the built-in mic on the computer and the TV sound popped. Then he pointed to Lazir's voice box and then back to the laptop. "Say something," he repeated. Lazir held his voice box over by the laptop and said "five, six, seven, eight."

When the TV image broke up again, Enoch shut down his streaming program, and out of the TV a voice like the voice box, not very loud, continued the count "nine, ten, eleven..." Enoch raised the TV volume a little and pointed in the general direction of the plane. "Lazir?" he asked.

Lazir said (through the voice box), "Meekya." That must be the name of one of the other guys in the plane. Sure enough, a face showed up on the TV. Enoch repeated "Meekya" and pointed to the face on the TV. "Meekya," Lazir agreed. The TV sound repeated the name. Then Meekya moved off-screen and another face appeared. It could have been the same guy, they all looked the same to Enoch, but he had a different name, something like "Zockry." Enoch wasn't very good at names, so he could not remember them, but they were clearly introducing themselves to him. He tried repeating the first two or three, then gave up. The image panned around the room; there might have been a half-dozen or more guys there. The names went by very fast.

Enoch wondered if they understood that the TV signals were also coming by radio. He had a satellite connection, but the dish was pointed to the sky; maybe they couldn't hack into that. Come to think of it, the satellite signal is encrypted, too. Otherwise nobody would pay for the service.

Enough technology, Enoch thought. Besides, he was ravenous.

Enoch went into the kitchen and came back with a bowl and a bag of chips. Not very healthy, he thought, but he'd just got back from California and didn't have any fresh food in the house. He had canned and frozen food, but both of them took preparation; this was not a good time to be cooking. He set the bowl on the coffee table, then tore open the bag and poured them out into the bowl. Lazir probably couldn't eat anything with his helmet on, but at least he'd offer. "Food," he announced, "chips," then picked up one and ate it. "Eat. Enoch eat [munch, munch], Lazir eat." Lazir tapped his helmet.

They had not yet discussed abstractions like negatives, but this was a teachable moment. Enoch seized it. "Enoch eat. Lazir not eat. Enoch eat." He took another chip and ate it. "Enoch not eat," he said and pushed the bowl away. "Enoch eat," he said, pulling it back and taking another chip. "Lazir not eat. Lazir wear helmet," he added, pointing to Lazir's helmet. Enoch wondered if he had anything like a helmet around. Did he bring that bicycle helmet when he packed up from California? If so, it would be in the box out in the garage. He ran through the kitchen out into the garage, pulled the box off the shelf, and dug through it. There it is! He grabbed the helmet and ran back to the living room waving the helmet. "Enoch wear helmet," he called out, and when he was back in view, he put his bicycle helmet on. "Enoch not eat," he said, "Enoch wear helmet." Then he took the helmet off and grabbed another chip and ate it. "Enoch not wear helmet. Enoch eat. Lazir not wear helmet, Lazir eat."

It was probably a bad idea. Maybe earth air is poisonous to them. Maybe the food is poisonous to them. It's not all that healthy for humans, at least not the chips. But Enoch was hungry. He ate. "Enoch hungry," he said, "Enoch eat. Enoch go to Enoch's house. Enoch eat. Lazir hungry? Lazir go to Lazir's house. Lazir eat."

Lazir didn't leave. "Lazir not go," he said. "Lazir talk. Enoch eat."
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