“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.”

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?”