DAY 12: ZINJ

June 24, 1979

1.The Offensive

SHORTLY AFTER DAWN, THEY DISCOVERED THE bodies of Mulewe and Akari near their tent. Apparently the attack the night before had been a diversion, allowing one gorilla to enter the compound, kill the porters, and slip out again. Even more disturbing, they could find no clue to how the gorilla had got through the electrified fence and back out again.

A careful search revealed a section of fence torn near the bottom. A long stick lay on the ground nearby. The gorillas had used the stick to lift the bottom of the fence, enabling one to crawl through. And before leaving, the gorillas had carefully restored the fence to its original condition.

The intelligence implied by such behavior was hard to accept. "Time and again," Elliot said later, "we came up against our prejudices about animals. We kept expecting the gorillas to behave in stupid, stereotyped ways but they never did. We never treated them as flexible and responsive adversaries, though they had already reduced our numbers by one fourth."

Munro had difficulty accepting the calculated hostility of the gorillas. His experience had taught him that animals in nature were indifferent to man. Finally he concluded that "these animals had been trained by men, and I had to think of them as men. The question became what would I do if they were men?"

For Munro the answer was clear: take the offensive.

Amy agreed to lead them into the jungle where she said the gorillas lived. By ten o'clock that morning, they were moving up the hillsides north of the city armed with machine guns. It was not long before they found gorilla spoor -  quantities of dung, and nests on the ground and in the trees. Munro was disturbed by what he saw; some trees held twenty or thirty nests, suggesting a large population of animals.

Ten minutes later, they came upon a group of ten gray gorillas feeding on succulent vines: four males and three females, a juvenile, and two scampering infants. The adults were lazy, basking in the sun, eating in desultory fashion. Several other animals slept on their backs, snoring loudly. They all seemed remarkably unguarded.

Munro gave a hand signal; the safeties clicked off the guns. He prepared to fire into the group when Amy tugged at his trouser leg. He looked off and "had the shock of my bloody life. Up the slope was another group, perhaps ten or twelve animals - and then I saw another group - and another - and another still. There must have been three hundred or more. The hillside was crawling with gray gorillas."

The largest gorilla group ever sighted in the wild had been thirty-one individuals, in Kabara in 1971, and even that sighting was disputed. Most researchers thought it was actually two groups seen briefly together, since the usual group size was ten to fifteen individuals. Elliot found three hundred animals "an awesome sight." But he was even more impressed by the behavior of the animals. As they browsed and fed in the sunlight, they behaved very much like ordinary gorillas in the wild, but there were important differences.

"From the first sighting, I never had any doubt that they had language. Their wheezing vocalizations were striking and clearly constituted a form of language. In addition they used sign language, although nothing like what we knew. Their hand gestures were delivered with outstretched arms in a graceful way, rather like Thai dancers. These hand movements seemed to complement or add to the sighing vocalizations. Obviously the gorillas had been taught, or had elaborated on their own, a language system far more sophisticated than the pure sign language of laboratory apes in the twentieth century."

Some abstract corner of Elliot's mind considered this discovery tremendously exciting, while at the same time he shared the fear of the others around him. Crouched behind the dense foliage they held their breath and watched the gorillas feed on the opposite hillside. Although the gorillas seemed peaceful, the humans watching them felt a tension approaching panic at being so close to such great numbers of them. Finally, at Munro's signal, they slipped back down the trail, and returned to the camp.

The porters were digging graves for Akari and Mulewe in camp. It was a grim reminder of their jeopardy as they discussed their alternatives. Munro said to Elliot, "They don't seem to be aggressive during the day."

"No," Elliot said. "Their behavior looks quite typical -  if anything,. it's more sluggish than that of ordinary gorillas in daytime. Probably most of the males are sleeping during the day."

"How many animals on the hillside are males?" Munro asked. They had already concluded that only male animals participated in the attacks; Munro was asking for odds.

Elliot said, "Most studies have found that adult males constitute fifteen percent of gorilla groupings. And most studies show that isolated observations underestimate troop size by twenty-five percent. There are more animals than you see at any given moment."

The arithmetic was disheartening. They had counted three hundred gorillas on the hillside, which meant there were probably four hundred, of which 15 percent were males. That meant that there were sixty attacking animals - and only nine in their defending group.

"Hard," Munro said, shaking his head.

Amy had one solution. She signed, Go now.

Ross asked what she said and Elliot told her, "She wants to leave. I think she's right."

"Don't be ridiculous," Ross said. "We haven't found the diamonds. We can't leave now."

Go now, Amy signed again.

They looked at Munro. Somehow the group had decided that Munro would make the decision of what to do next. "I want the diamonds as much as anyone," he said. "But they won't be much use to us if we're dead. We have no choice. We must leave if we can."

Ross swore, in florid Texan style.

Elliot said to Munro, "What do you mean, if we can?"

"I mean," Munro said, "that they may not let us leave."

2.Departure

FOLLOWING MUNRO'S INSTRUCTIONS, THEY carried only minimal supplies of food and ammunition. They left everything else - the tents, the perimeter defenses, the communications equipment, everything, in the sunlit clearing at midday.

Munro glanced back over his shoulder and hoped he was doing the right thing. In the 1960s, the Congo mercenaries had had an ironic rule: "Don't leave home." It had multiple meanings, including the obvious one that none of them should ever have come to the Congo in the first place. It also meant that once established in a fortified camp or colonial town you were unwise to step out into the surrounding jungle, whatever the provocation. Several of Munro's friends had bought it in the jungle because they had foolishly left home. The news would come to them: "Digger bought it last week outside Stanleyville." "Outside? Why'd he leave home?"

Munro was leading the expedition outside now, and home was the little silver camp with its perimeter defense behind them. Back in that camp, they were sitting ducks for the attacking gorillas. The mercenaries had had something to say about that, too: "Better a sitting duck than a dead duck."

As they marched through the rain forest, Munro was painfully aware of the single-file column strung out behind him, the least defensible formation. He watched the jungle foliage move in as their path narrowed. He did not remember this track being so narrow when they had come to the city. Now they were hemmed in by close ferns and spreading palms.

The gorillas might be only a few feet away, concealed in the dense foliage, and they wouldn't know it until it was too late.

They walked on.

Munro thought if they could reach the eastern slopes of Mukenko, they would be all right. The gray gorillas were localized near the city, and would not follow them far. One or two hours walking, and they would be beyond danger.

He checked his watch: they had been gone ten minutes.

And then he heard the sighing sound. It seemed to come from all directions. He saw the foliage moving before him, shifting as if blown by a wind. Only there was no wind. He heard the sighing grow louder.

The column halted at the edge of a ravine, which followed a streambed past sloping jungle walls on both sides. It was the perfect spot for an ambush. Along the line he heard the safeties click on the machine guns. Kahega came up. "Captain, what do we do?"

Munro watched the foliage move,, and heard the sighing. He could only guess at the numbers concealed in the bush. Twenty? Thirty? Too many, in any case.

Kahega pointed up the hillside to a track that ran above the ravine. "Go up there?"

For a long time, Munro did not answer. Finally, he said, "No, not up there."

"Then where, Captain?"

"Back," Munro said. "We go back."

When they turned away from the ravine, the sighing faded and the foliage ceased its movement. When he looked back over his shoulder for a last glimpse, the ravine appeared an ordinary passage in the jungle, without threat of any kind. But Munro knew the truth. They could not leave.

3.Return

ELLIOT'S IDEA CAME IN A FLASH OF INSIGHT. "IN the middle of the camp," he later related, "I was looking at Amy signing to Kahega. Amy was asking him for a drink, but Kahega didn't know Ameslan, and he kept shrugging helplessly. It occurred to me that the linguistic skill of the gray gorillas was both their great advantage and their Achilles' heel."

Elliot proposed to capture a single gray gorilla, learn its language, and use that language to establish communication with the other animals. Under normal circumstances it would take several months to learn a new ape language, but Elliot thought he could do it in a matter of hours.

Seamans was already at work on the gray-gorilla verbalizations; all he needed was further input. But Elliot had decided that the gray gorillas employed a combination of spoken sounds and sign language. And the sign language would be easy to work out.

Back at Berkeley, Seamans had developed a computer program called APE, for animal pattern explanation. APE was capable of observing Amy and assigning meanings to her signs. Since the APE program utilized declassified army software subroutines for code-breaking, it was capable of identifying new signs, and translating these as well. Although APE was intended to work with Amy in ASL, there was no reason why it would not work with an entirely new language.

If they could forge satellite links from the Congo to Houston to Berkeley, they could feed video data from a captive animal directly into the APE program. And APE promised a speed of translation far beyond the capacity of any human observer. (The army software was designed to break enemy codes in minutes.)

Elliot and Ross were convinced it would work; Munro was

not. He made some disparaging comments about interrogating prisoners of war. "What do you intend to do," he said, "torture the animal?"

"We will employ situational stress," Elliot said, "to elicit language usage." He was laying out test materials on the ground: a banana, a bowl of water, a piece of candy, a stick, a succulent vine, stone paddles. "We'll scare the hell out of her if we have to."

"Her?"

"Of course," Elliot said, loading the Thoralen dart gun. "Her.''

4.Capture

HE WANTED A FEMALE WITHOUT AN INFANT. An infant would create difficulties.

Pushing through waist-high undergrowth, he found himself on the edge of a sharp ridge and saw nine animals grouped below him: two males, five females, and two juveniles. They were foraging through the jungle twenty feet below. He watched the group long enough to be sure that all the females used language, and that there were no infants Concealed in the foliage. Then he waited for his chance.

The gorillas fed casually among the ferns, plucking up tender shoots, which they chewed lazily. After several minutes, one female moved up from the group to forage nearer the top of the ridge where he was crouching. She was separated from the rest of the group by more than ten yards.

Elliot raised the dart pistol in both hands and squinted down the sight at the female. She was perfectly positioned.

He watched, squeezed the trigger slowly - and lost his footing on the ridge. He fell crashing down the slope, right into the midst of the gorillas.

Elliot lay unconscious on his back, twenty feet below, but his chest was moving, and his arm twitched; Munro felt certain that he was all right. Munro was only concerned about the gorillas.

The gray gorillas had seen Elliot fall and now moved toward the body. Eight or nine animals clustered around him, staring impassively, signing.

Munro slipped the safety off his gun.

Elliot groaned, touched his head, and opened his eyes. Munro saw Elliot stiffen as he saw the gorillas, but he did not move. Three mature males crouched very close to him, and he understood the precariousness of his situation. Elliot lay motionless on the ground for nearly a minute. The gorillas whispered and signed, but they did not come any closer.

Finally Elliot sat up on one elbow, which caused a burst of signing but no direct threatening behavior.

On the hillside above, Amy tugged at Munro's sleeve, signing emphatically. Munro shook his head: he did not understand; he raised his machine gun again, and Amy bit his kneecap. The pain was excruciating. It was all Munro could do to keep from screaming.

Elliot, lying on the ground below, tried to control his breathing. The gorillas were very close - close enough for him to touch them, close enough to smell the sweet, musty odor of their bodies. They were agitated; the males had started grunting, a rhythmic ho-ho-ho.

He decided he had better get to his feet, slowly and methodically. He thought that if he could put some distance between himself and the animals, their sense of threat would be reduced. But as soon as he began to move the grunting grew louder, and one of the males began a sideways crablike movement, slapping the ground with his flat palms.

Immediately Elliot lay back down. The gorillas relaxed,

and he decided he had done the correct thing. The animals were confused by this human being crashing down in their midst; they apparently did not expect contact with men in foraging areas.

He decided to wait them out, if necessary remaining on his back for several hours until they lost interest and moved off. He breathed slowly, regularly, aware that he was sweating. Probably he smelled of fear - but like men, gorillas had a poorly developed sense of smell. They did not react-to the odor of fear. He waited. The gorillas were sighing and signing swiftly, trying to decide what to do. Then one male abruptly resumed his crabwise movements, slapping the ground and staring at Elliot. Elliot did not move. In his mind, he reviewed the stages of attack behavior: grunting, sideways movement, slapping, tearing up grass, beating chest -  Charging.

The male gorilla began tearing up grass. Elliot felt his heart pounding. The gorilla was a huge animal, easily three hundred pounds. He reared up on his hind legs and beat his chest with flat palms, making a hollow sound. Elliot wondered what Munro was doing above. And then he heard a crash, and he looked to see Amy tumbling down the hillside, breaking her fall by grabbing at branches and ferns. She landed at Elliot's feet.

The gorillas could not have been more surprised. The large male ceased beating his chest, dropped down from his upright posture, and glowered at Amy.

Amy grunted.

The large male moved menacingly toward Peter, but he never took his eyes off Amy. Amy watched him without response. It was a clear test of dominance. The male moved closer and closer, without hesitation.

Amy bellowed, a deafening sound; Elliot jumped in surprise. He had only heard her do it once or twice before in moments of extreme rage. It was unusual for females to roar, and the other gorillas were alarmed. Amy's forearms stiffened, her back went rigid, her face became tense. She stared aggressively at the male and roared again.

The male paused, tilted his head to one side. He seemed to be thinking it over. Finally he hacked off, rejoining the semicircle of gray apes around Elliot's head.

Amy deliberately rested her hand on Elliot's leg, establishing possession. A juvenile male, four or five years old, impulsively scurried forward, baring his teeth. Amy slapped him across the face, and the juvenile whined and scrambled back to the safety of his group.

Amy glowered at the other gorillas. And then she began signing. Go away leave Amy go away.

The gorillas did not respond.

Peter good human person. But she seemed to be aware that the gorillas did not understand, for she then did something remarkable: she sighed, making the same wheezing sound that the gorillas made.

The gorillas were startled, and stared at one another.

But if Amy was speaking their language, it was without effect: they remained where they were. And the more she sighed, the more their reaction diminished, until finally they stared blandly at her.

She was not getting through to them.

Amy now came alongside Peter's head and began to groom him, plucking at his beard and scalp. The gray gorillas signed rapidly. Then the male began his rhythmic ho-ho-ho once more. When she saw this Amy turned to Peter and signed, Amy hug Peter. He was surprised: Amy never volunteered

to hug Peter. Ordinarily she only wanted Peter to hug and tickle Amy.

Elliot sat up and she immediately pulled him to her chest, pressing his face into her hair. At once the male gorilla ceased grunting. The gray gorillas began to backpedal, as if they

had committed some error. In that moment, Elliot under-

stood: she was treating him like her infant.

This was classic primate behavior in aggressive situations. Primates carried strong inhibitions against harming infants, and this inhibition was invoked by adult animals

in many contexts. Male baboons often ended their fight when one male grabbed an infant and clutched it to his chest; the sight of the small animal inhibited further attack. Chimpanzees showed wore subtle variations of the same thing. If juvenile chimp play turned too brutal, a male would grab one juvenile and clutch it maternally, even though in this case both parent and child were symbolic. Yet the posture was sufficient to evoke the inhibition against further violence. In this case Amy was not only halting the male's attack but protecting Elliot as well, by treating him as an infant - if the gorillas would accept a bearded six-foot-tall infant.

They did.

They disappeared hack into the foliage. Amy released Elliot from her fierce grip. She looked at him and signed, Dumb things.

"Thank you, Amy," he said and kissed her.

Peter tickle Amy Amy good gorilla.

"You bet," he said, and he tickled her for the next several minutes, while she rolled on the ground, grunting happily.

It was two o'clock in the afternoon when they returned to camp. Ross said, "Did you get a gorilla?"

"No," Elliot said.

"Well, it doesn't matter," Ross, said, "because I can't raise Houston."

Elliot was stunned: "More electronic jamming?"

"Worse than that," Ross said. She had spent an hour trying to establish a satellite link with Houston, and had failed. Each time the link was broken within seconds. Finally, after confirming that there was no fault with her equipment, she had checked the date. "It's June 24," she said. "And we had communications trouble with the last Congo expedition on May 28. That's twenty-seven days ago."

When Elliot still didn't get it, Munro said, "She's telling you it's solar."

"That's right," Ross said. "This is an ionospheric disturbance of solar origin." Most disruptions of the earth's ionosphere - the thin layer of ionized molecules 50-250 miles up - were caused by phenomena such as sunspots on the surface of the sun. Since the sun rotated every twenty-seven days, these disturbances often recurred a month later.

''Okay," Elliot said, "it's solar. How long will it last?"

Ross shook her head. "Ordinarily, I would say a few hours, a day at most. But this seems to be a severe disturbance and it's come up very suddenly. Five hours ago we had perfect communications - and now we have none at all. Something unusual is going on. It could last a week."

"No communications for a week? No computer tie-ins, no nothing?"

"That's right," Ross said evenly. "From this moment on, we are entirely cut off from the outside world."

5. Isolation

THE LARGEST SOLAR FLARE OF 1979 WAS RECORDED on June 24, by the Kitt Peak Observatory near Tucson, Arizona, and duly passed on to the Space Environment Services Center in Boulder, Colorado. At first the SESC did not believe the incoming data: even by the gigantic standards of solar astronomy, this flare, designated 78/06/4l4aa, was a monster.

The cause of solar flares is unknown, but they are generally associated with sunspots. In this case the flare appeared as an extremely bright spot ten thousand miles in diameter, affecting not only alpha hydrogen and ionized calcium spectral lines but also the white light spectrum from the sun. Such a "continuous spectrum" flare was extremely rare.

Nor could the SESC believe the computed consequences. Solar flares release an enormous amount of energy; even a modest flare can double the amount of ultraviolet radiation emitted by the entire solar surface. But flare 78/06/4l4aa was almost tripling ultraviolet emissions. Within 8.3 minutes of its first appearances along the rotating rim - the time it takes light to reach the earth from the sun - this surge of ultraviolet radiation began to disrupt the ionosphere of the earth.

The consequence of the flare was that radio communications on a planet ninety-three million miles away were seriously disrupted. This was especially true for radio transmissions which utilized low signal strengths. Commercial radio stations generating kilowatts of power were hardly

inconvenienced, but the Congo Field Survey, transmitting signals on the order of twenty thousand watts, was unable to establish satellite links. And since the solar flare also ejected X-rays and atomic particles which would not reach the earth for a full day, the radio disruption would last at least one day, and perhaps longer. At ERTS in Houston, technicians reported to Travis that the SESC predicted a time course of ionic disruption of four to eight days.

"That's how it looks. Ross'll probably figure it out," the technician said, "when she can't re-establish today."

"They need that computer hookup," Travis said. The ERTS staff had run five computer simulations and the outcome was always the same - short of airlifting in a small army, Ross's expedition was in serious trouble. Survival projections were running "point two four four and change" -  only one chance in four that the Congo expedition would get out alive, assuming the help of the computer link which was now broken.

Travis wondered if Ross and the others realized how grave their situation was. "Any new Band Five on Mukenko?" Travis asked.

Band 5 on Landsat satellites recorded infrared data. On its last pass over the Congo, Landsat had acquired significant new information on Mukenko. The volcano had become much hotter in the nine days since the previous Landsat pass; the temperature increase was on the order of 8 degrees.

"Nothing new," the technician said. "And the computers don't project an eruption. Four degrees of orbital change are Within sensor error on that system, and the additional four degrees have no predictive value."

"Well, that's something," Travis said. "But what are they going to do about the apes now that they're cut off from the computer?"

That was the question the Congo Field Survey had been asking themselves for the better part of an hour. With communications disrupted the only computers available were the computers in their own heads. And those computers were not powerful enough.

Elliot found it strange to think that his own brain was inadequate. "We had all become accustomed to the availability of computing power," he said later. "In any decent laboratory you can get all the memory and all the computation speed you could want, day or night. We were so used to it we had come to take it for granted.

Of course they could have eventually worked out the ape language, but they were up against a time factor: they didn't have months to puzzle it out; they had hours. Cut off from the APE program their situation was ominous. Munro said that they could not survive another night of frontal attack, and they had every reason to expect an attack that night.

Amy's rescue of Elliot suggested their plan. Amy had shown some ability to communicate with the gorillas; perhaps she could translate for them as well. "It's worth a try," Elliot insisted.

Unfortunately, Amy herself denied that this was possible. In response to the question "Amy talk thing talk?" She

signed, No talk.

"Not at all?" Elliot said, remembering the way she had signed. "Peter see Amy talk thing talk."

No talk. Make noise.

He concluded from this that she was able to mimic the gorilla verbalizations but had no knowledge of their meaning. It was now past two; they had only four or five hours until nightfall.

Munro said, "Give it up. She obviously can't help us." Munro preferred to break camp and fight their way out in daylight. He was convinced that they could not survive another night among the gorillas.

But something nagged at Elliot's mind.

After years of working with Amy, he knew she had the maddening literal-mindedness of a child. With Amy, especially when she was feeling uncooperative, it was necessary to be exact to elicit the appropriate response. Now he looked at Amy and said, "Amy talk thing talk?"

No talk.

"Amy understand thing talk?"

Amy did not answer. She was chewing on vines, preoccupied.

"Amy, listen to Peter." She stared at him. "Amy understand thing talk?"

Amy understand thing talk, she signed back. She did it so matter-of-factly that at first he wondered if she realized what he was asking her.

"Amy watch thing talk, Amy understand talk?"

Amy understand.

"Amy sure?"

Amy sure.

"I'll be goddamned," Elliot said.

Munro was shaking his head. "We've only got a few hours

of daylight left," he said. "And even if you do learn their language, how are you going to talk to them?"

6.Amy Talk Thing Talk

AT 3 P.M., ELLIOT AND AMY WERE COMPLETELY concealed in the foliage along the hillside. The only sign of their presence was the slender cone of the microphone that protruded through the foliage. The microphone was connected to the videotape recorder at Elliot's feet, which he used to record the sounds of the gorillas on the hills beyond.

The only difficulty was trying to determine which gorilla the directional microphone had focused on - and which gorilla Amy had focused on, and whether they were the same gorilla. He could never be quite sure that Amy was translating the verbal utterances of the same animal that he was recording. There were eight gorillas in the nearest group and Amy kept getting distracted. One female had a six-month-old infant, and at one point, when the baby was bitten by a bee, Amy signed, Baby mad. But Elliot was recording a male.

Amy, he signed. Pay attention.

Amy pay attention. Amy good gorilla.

Yes, he signed. Amy good gorilla. Amy pay attention man thing.

Amy not like.

He swore silently, and erased half an hour of translations from Amy. She had obviously been paying attention to the wrong gorilla. When he started the tape again, he decided that this time he would record whatever Amy was watching. He signed, What thing Amy watch?

Amy watch baby.

That wouldn't work, because the baby didn't speak. He signed, Amy watch woman thing.

Amy like watch baby.

This dependency on Amy was like a bad dream. He was in the hands of an animal whose thinking and behavior he barely understood; he was cut off from the wider society of human beings and human machinery, thus increasing his dependency on the animal; and yet he had to trust her.

After another hour, with the sunlight fading, he took Amy back down the hillside to the camp.

Munro had planned as best he could.

First he dug a series of holes like elephant traps outside the camp; they were deep pits lined with sharp stakes, covered with leaves and branches.

He widened the moat in several places, and cleared away dead trees and underbrush that might be used as bridges.

He cut down the low tree branches overhanging the camp, so that if gorillas went into the trees, they would be kept at least thirty feet above the ground - too high to jump down.

He gave three of the remaining porters, Muzezi, Amburi, and Harawi, shotguns along with a supply of tear-gas canisters.

With Ross, he boosted power on the perimeter fence to almost 200 amps. This was the maximum the thin mesh could handle without melting; they had been obliged to reduce the pulses from four to two per second. But the additional current changed the fence from a deterrent to a lethal barrier. The first animals to hit that fence would be immediately killed, although the likelihood of shorts and a dead fence was considerably increased.

At sunset, Munro made his most difficult decision. He loaded the stubby tripod-mounted RFSDs with half their remaining ammunition. When that was gone, the machines would simply stop firing. From that point on, Munro was counting on Elliot and Amy and their translation.

And Elliot did not look very happy when he came back down the hill.

7.Final Defense

"How LONG UNTIL YOU'RE READY?" MUNRO asked him.

"Couple of hours, maybe more." Elliot asked Ross to help him, and Amy went to get food from Kahega. She seemed very proud of herself, and behaved like an important person in the group.

Ross said, "Did it work?"

"We'll know in a minute," Elliot said. His first plan was to run the only kind of internal check on Amy that he could, by verifying repetitions of sounds. If she had consistently translated sounds in the same way, they would have a reason for confidence.

But it was painstaking work. They had only the half-inch VTR and the small pocket tape recorder; there were no connecting cables. They called for silence from the others in the camp and proceeded to run the checks, taping, retaping, listening to the whispering sounds.

At once they found that their ears simply weren't capable of discriminating the sounds - everything sounded the same. Then Ross had an idea.

"These sounds taped," she said, "as electrical signals."

"Yes . .

"Well, the linkup transmitter has a 256K memory."

"But we can't link up to the Houston computer."

"I don't mean that," Ross said. She explained that the satellite linkup was made by having the 256K computer on-site match an internally generated signal - like a video test pattern - to a transmitted signal from Houston. That was how they locked on. The machine was built that way, but they could use the matching program for other purposes.

"You mean we can use it to compare these sounds?" Elliot said.

They could, but it was incredibly slow. They had to transfer the taped sounds to the computer memory, and rerecord it in the VTR, on another portion of the tape bandwidth. Then they had to input that signal into the computer memory, and run a second comparison tape on the VTR. Elliot found that he was standing by, watching Ross shuffle tape cartridges and mini floppy discs. Every half hour, Munro would wander over to ask how it was coming; Ross became increasingly snappish and irritable. "We're going as fast as we can," she said.

It was now eight o'clock.

But the first results were encouraging: Amy was indeed consistent in her translations. By nine o'clock they had quantified matching on almost a dozen words:

FOOD .9213 .112

EAT .8844 .334

WATER .9978 .004

DRINK .7743 .334

{AFFIRMATION} YES .6654 .441

{NEGATION} NO .8883 .220

COME  .5459 .440

GO   .5378 .404

SOUND COMPLEX: ?AWAY .5444 .363

SOUND COMPLEX: ?HERE .6344 .344

SOUND COMPLEX: ?ANGER

  ?BAD .4232 .477

Ross stepped away from the computer. "All yours," she said to Elliot.

Munro paced across the compound. This was the worst time. Everyone waiting, on edge, nerves shot. He would have joked with Kahega and the other porters, but Ross and

-Elliot needed silence for their work. He glanced at Kahega. Kahega pointed to the sky and rubbed his fingers together. Munro nodded.

He had felt it too, the heavy dampness in the air, the almost palpable feeling of electrical charge. Rain was coming.

That was all they needed, he thought. During the afternoon, there had been more booming and distant explosions, which

he had thought were far-off lightning storms. But the sound was not right; these were sharp, single reports, more like a sonic boom than anything else. Munro had heard them before, and he had an idea about what they meant.

He glanced up at the dark cone of Mukenko, and the faint glow of the Devil's Eye. He looked at the crossed green laser beams overhead. And he noticed one of the beams was moving where it struck foliage in the trees above.

At first he thought it was an illusion, that the leaf was moving and not the beam. But after a moment he was sure: the beam itself was quivering, shifting up and down in the night air.

Munro knew this was an ominous development, but it would have to wait until later; at the moment, there were more pressing concerns. He looked across the compound at Elliot and Ross bent over their equipment, talking quietly and in general behaving as if they had all the time in the world.

Elliot actually was going as fast as he could. He had eleven reliable vocabulary words recorded on tape. His problem now was to compose an unequivocal message. This was not as easy as it first appeared.

For one thing, the gorilla language was not a pure verbal language. The gorillas used sign and sound combinations to convey information. This raised a classic problem in language structure - how was the information actually conveyed? (L. S. Verinski once said that if alien visitors watched Italians speaking they would conclude that Italian was basically a gestural sign language, with sounds added for emphasis only.) Elliot needed a simple message that did not depend on accompanying hand signs.

But he had no idea of gorilla syntax, which could critically alter meaning in most circumstances - the difference between "me beat" and "beat me." And even a short message could be ambiguous in another language. In English, "Look out!" generally meant the opposite of its literal meaning.

Faced with these uncertainties, Elliot considered broadcasting a single word. But none of the words on his list was suitable. His second choice was to broadcast several short messages, in case one was inadvertently ambiguous. He eventually decided on three messages; GO AWAY, NO COME, and BAD HERE; two of these combinations had the virtue of being essentially independent of word order.

By nine o'clock, they had already isolated the specific sound components. But they still had a complicated task ahead. What Elliot needed was a loop, repeating the sounds over and over. The closest they would come was the VCR, which rewound automatically to play its message again. He could hold the six sounds in the 256K memory and play them out, but the timing was critical. For the next hour, they frantically worked at the keyboard, trying to bring the word combinations close enough together to sound - to their ears -  correct.

By then it was after ten.

Munro came over with his laser gun. "You think all this

will work?"

Elliot shook his head. "There's no way to know." A dozen objections had come to mind. They had recorded a female voice, but would the gorillas respond to a female? Would they accept voice sounds without accompanying hand signals? Would the message be clear? Would the spacing of the sounds be acceptable? Would the gorillas pay attention at all?

There was no way to know. They would simply have to try. Equally uncertain was the problem of broadcasting. Ross had made a speaker, removing the tiny speaker from the pocket tape recorder and gluing it to an umbrella on a collapsible tripod. This makeshift speaker produced surprisingly loud volume, but reproduction was muffled and unconvincing.

Shortly afterward, they heard the first sighing sounds.

Munro swung the laser gun through the darkness, the red activation light glowing on the electronic pod at the end of the barrel. Through his night goggles he surveyed the foliage.

Once again, the sighing came from all directions; and although he heard the jungle foliage shifting, he saw no movement close to the camp. The monkeys overhead were silent. There was only the soft, ominous sighing. Listening now, Munro was convinced that the sounds represented a language of some form, and -  A single gorilla appeared and Kahega fired, his laser beam

streaking arrow-straight through the night. The RFSD chattered and the foliage snapped with bullets. The gorilla ducked silently back into a stand of dense ferns.

Munro and the others quickly took positions along the perimeter, crouching tensely, the infrared night lights casting their shadows on the mesh fence and the jungle beyond.

The sighing continued for several minutes longer, and then slowly faded away, until all was silent again.

"What was that about?" Ross said.

Munro frowned. "They're waiting."

"For what?"

Munro shook his head. He circled the compound, looking at the oilier guards, trying to work it out. Many times he had anticipated the behavior of animals - a wounded leopard in the bush, a cornered buffalo - but this was different. He was forced to admit he didn't know what to expect. Had the single gorilla been a scout to look at their defenses? Or had an attack actually begun, only for some reason to be halted? Was it a maneuver designed to fray nerves? Munro had watched parties of hunting chimpanzees make brief threatening forays toward baboons, to raise the anxiety level of the entire troop before the actual assault, isolating some young animal for killing.

Then he heard the rumble of thunder. Kahega pointed to the sky, shaking his head. That was their answer.

"Damn," Munro said.

At 10:30 a torrential tropical rain poured down on them. Their fragile speaker was immediately soaked and drooping.

The rain shorted the electrical cables and the perimeter fence went dead. The night lights flickered, and two bulbs exploded. The ground turned to mud; visibility was reduced to five yards. And worst of all, the rain splattering the foliage was so noisy they had to shout to each other. The tapes were unfinished; the loudspeaker probably would not work, and certainly would not carry over the rain. The rain would interfere with the lasers and prevent the dispersal of tear gas. Faces in camp were grim.

Five minutes later, the gorillas attacked.

The rain masked their approach; they seemed to burst out of nowhere, striking the fence from three directions simultaneously. From that first moment, Elliot realized the attack would be unlike the others. The gorillas had learned from the earlier assaults, and now were intent on finishing the job.

Primate attack animals, trained for cunning and viciousness: even though that was Elliot's own assessment, he was astonished to see the proof in front of him. The gorillas charged in waves, like disciplined shock troops. Yet he found it more horrifying than an attack by human troops. lb them we are just animals, he thought. An alien species, for which they have no feeling. We are just pests to be eliminated.

These gorillas did not care why human beings were there, or what reasons had brought them to the Congo. They were not killing for food, or defense, or protection of their young.

They were killing because they were trained to kill.

The attack proceeded with stunning swiftness. Within seconds, the gorillas had breached the perimeter and trampled the mesh fence into the mud. Unchecked, they rushed into the compound, grunting and roaring. The driving rain matted their hair, giving them a sleek, menacing appearance in the red night lights. Elliot saw ten or fifteen animals inside the compound, trampling the tents and attacking the people. Azizi was killed immediately, his skull crushed between paddles.

Munro, Kahega, and Ross all fired laser bursts, but in the confusion and poor visibility their effectiveness was limited. The laser beams fragmented in the slashing rain; the tracer bullets hissed and sputtered. One of the RFSDs went haywire, the barrel swinging in wide arcs, bullets spitting out in all directions, while everyone dived into the mud. Several gorillas were killed by the RFSD bursts, clutching their chests in a bizarre mimicry of human death.

Elliot turned back to the recording equipment and Amy flung herself on him, panicked, grunting in fear. He pushed her away and switched on the tape replay.

By now the gorillas had overwhelmed everyone in the camp. Munro lay on his back, a gorilla on top of him.- Ross was nowhere to be seen. Kahega had a gorilla clinging to his chest as he rolled in the mud. Elliot was hardly aware of the hideous scratching sounds now emanating from the loudspeaker, and the gorillas themselves paid no attention.

Another porter, Muzezi, screamed as he stepped in front of a firing RFSD; his frame shook with the impact. of the bullets and he fell backward to the ground, his body smoking from the tracers. At least a dozen gorillas were dead or lying. wounded in the mud, groaning. The haywire RFSD had run out of ammunition; the barrel swung back and forth, the empty chamber clicking. A. gorilla kicked it over, and it lay writhing on its side in the mud like a living thing as the barrel continued to swing.

Elliot saw one gorilla crouched over, methodically tearing a tent apart, shredding the silver MyLar into strips. Across the camp, another arrival banged aluminum cook pans together, as if they were metal paddles. More gorillas poured into the compound, ignoring the rasping broadcast sounds.

He saw a gorilla pass beneath the loudspeaker, very close, and pay no attention at all. Elliot had the sickening realization that their plan had failed.

They were finished; it was only a matter of time. A gorilla charged him, bellowing in rage, swinging stone paddles wide. Terrified, Amy threw her hands over Elliot's eyes. "Amy!" he shouted, pulling her fingers away, expecting to feel at any moment the impact of the paddles and the instant of blinding pain.

He saw the gorilla hearing down on him. He tensed his body. Six feet away, the charging gorilla stopped so abruptly that he literally skidded in the mud and fell backward. He sat there surprised, cocking his head, listening.

Then Elliot realized that the rain had nearly stopped, that there was now only a light drizzle sifting down over the campsite. Looking across the compound, Elliot saw another gorilla stop to listen - then another - and another - and another. The compound took on the quality of a frozen tableau, as the gorillas stood silent in the mist.

They were listening to the broadcast sounds.

He held his breath, not daring to hope. The gorillas seemed uncertain, confused by the sounds they heard. Yet Elliot sensed that at any moment they could arrive at some group decision and resume their attack with the same intensity as before.

That did not happen. The gorillas stepped away from the people, listening. Munro scrambled to his feet, raising his gun from the mud. but he did not shoot; the gorilla standing over him seemed to be in a trance, to have forgotten all about the attack.

In the gentle rain, with the flickering night lights, the gorillas moved away, one by one. They seemed perplexed, off balance. The rasping continued over the loudspeaker.

The gorillas left, moving back across the trampled perimeter fence, disappearing once more into the jungle. And then the expedition members were alone, staring at each other, shivering in the misty rain. The gorillas were gone.

Twenty minutes later, as they were trying to rebuild their shattered campsite, the rain poured down again with unabated fury.