"You didn't say anything to Michael about the problems you found with the pod navigation," Nicole said. She and Richard were lying side by side in one of the small bedrooms on the military ship.

"No," replied Richard quietly. "I didn't want to worry him. He believes that we are going to be safe and I don't want him to think differently."

Nicole extended her arm and touched Richard. "We could stay here, darling-then at least Michael would survive." He rolled over toward her. She could tell he was looking at her, even though she couldn't see him very clearly in the dark. "I thought about that," Richard said. "But he would never accept it. ... I even thought about sending you by yourself. Would you want to do that?"

"No," Nicole answered after thinking for a moment. "I don't think so. I'd rather go with you, unless--"

"Unless what?"

"Unless there really is a big difference in the odds. If one of us can survive but two of us are almost certainly doomed, it doesn't make much sense-"

"I can't give you an accurate probabilistic a.s.sessment," Richard interrupted. "But I don't think there's a major difference if we go together. My knowledge of the pod and its system might almost be worth the extra ma.s.s. But either way, we're better off in the pod than if we stay here."

"You're absolutely convinced that missiles are on the way, aren't you?"

"Yes, indeed. Nothing else makes sense. I would bet that such a contingency plan was under development as soon as Rama changed course and headed for the Earth." They were silent again. Nicole tried to sleep but was unsuccessful. They had both decided to rest for six hours before departing so that they could store some energy for what would doubtless be an exhausting voyage. Nicole's mind, however, would not turn off. She kept imagining General O'Toole perishing in a nuclear fireball.

"He really is a wonderful man," Nicole said very quietly. She wasn't certain if Richard was still awake.

"Yes, he is," Richard answered in the same tone. "I envy his inner strength. I can't imagine giving up my own life for someone else so willingly," He paused for a moment. "I guess that comes from his deep religious beliefs. He doesn't see death as an end, only as a transition."

I could do it, Nicole thought. I could give up my life for Genevieve. Maybe even for Richard and this unborn baby. Perhaps in O'Toole's religion everyone is part of his family. Richard, meanwhile, was struggling with his own emotions. Was he being selfish in not insisting that Nicole go alone?

Could he really justify the extra risk of his presence in terms of his extra skills? He dismissed the questions and tried to think of something else.

"You haven't said much about the baby," Nicole said softly after another short silence.

"I haven't really had time to integrate him, or her, into what's going on," Richard replied. "I guess I've been insensitive. . . . You know I'm happy about it. I just want to wait until we're rescued before I seriously start thinking about what it will be like to be a father." He leaned over and gave Nicole a kiss. "Now, darling, I hope you won't think I'm being rude, but I'm going to try to sleep. It could be a long time before we have another opportunity-"

"Of course," she said. "I'm sorry." Nicole's mind drifted to another picture, this one of a small baby. / wonder if he'll be intelligent, she thought. And will he have Richard's blue eyes and long fingers?

Nicole was curled up in a ball in the corner of the dimly lit room. The taste of manna melon was still in her mouth. She was awakened by a strange tapping on her shoulder. Nicole glanced up and saw the gray velvet avian bending over her. The cherry rings around its neck glowed in the dark.

"Come," it said pleadingly. "You must come with us." She followed the avian into the hallway and turned to the right, away from the vertical corridor. The other avians were standing quietly against the wall. They were all watching her carefully. The whole procession followed the gray avian down the tunnel.

In a few moments the tunnel expanded into a large room. There was a solitary small light on the far wall, but otherwise the room was dark. Others were present, but Nicole could not see them clearly. Occasionally she glimpsed their silhouettes as they moved across the beam from the single light source. Nicole started to say something but the avian leader interrupted her. "Shh," it said, "they will be here soon."

Nicole heard a noise coming toward them from the opposite side of the room. It sounded like a cart with wooden wheels moving on a dirt path. As it approached, the avians around Nicole backed up and pressed against her. Moments later there was a fire in front of them.

A bier was resting on top of a burning cart. Nicole gasped. Her mother's body, dressed in regal green robes, lay on top of the bier. In the light from the fire Nicole could see some of the others in the room. Richard was smiling at her, holding the hand of a dark little girl about two years old. General O'Toole was very close to the fire, kneeling in prayer beside it. Behind him were a variety of biots and two or three odd forms that must have been octospiders. The flames consumed the bier and began to burn her mother's body. Her mother rose slowly from her supine position, When Anawi turned in Nicole's direction, her face changed. It was Omen's head on top of her mother's body.

"Ronata," he said distinctly, "the prophecies must be heeded. The Senoufo blood will be spread, even unto the stars. Minowe will be left behind. Ronata must travel with those who come from far away. Go now, and save the strange ones and Ronata's children."

60 RETURN TO RAMA.

I can't believe I'm doing this, Nicole said to herself as she carried her final ferryload of supplies to the heavy elevator at the top of the Beta stairway. It was dark inside Rama. The beam from her flashlight shone into the black void, The dream had been so incredibly vivid that Nicole had been completely dis...o...b..bulated for more than five minutes after she woke up. Even now, almost two hours later, when she closed her eyes Nicole could see Omeh's face perfectly and hear his magical voice intoning the words. I hope Richard doesn't wake up before I'm gone, Nicole thought. There's no way he would ever understand.

She returned to the ferry and made one last trip through the sh.e.l.l toward the Newton. For thirty minutes she had been drafting her good-bye remarks in her mind, but now that the moment had come, Nicole was apprehensive.

"Dear Michael and dearest Richard," she would begin, "last night I had the most compelling dream of my life. The old Senoufo chieftain Omeh appeared to me and told me that my destiny was with Rama."

Nicole pa.s.sed through the airlock and entered the control center. She sat down in front of the camera and cleared her voice. This is ridiculous, she thought, just before she turned on the lights. / must be insane. But the power of Omeh's image in her mind calmed all of her last-minute doubts, Moments later she continued with her final remarks to her friends.

"There is no way I can summarize in this short farewell the importance of Omeh and my African background in my life. Michael, Richard can tell you some of the Senoufo stories as the two of you fly home to Earth. Suffice it to say that I have never been misled by the old shaman. I know well that voices in a dream have no substance and are most likely creations of my own subconscious, but nevertheless I have decided to follow the directions Omeh gave me.

"I intend to do whatever I can to communicate to Rama that nuclear missiles may be on the way. I don't know exactly how I will accomplish this, but I will have some hours to plan while I am a.s.sembling the sailboat to cross the Cylindrical Sea. I do remember, Richard, our discussion about the keyboard commands that might lead into the higher hierarchy. . . .

"It is extremely difficult for me to say good-bye like this, and I am keenly aware that it is a poor subst.i.tute for a final embrace. But if you two were awake, you would never let me go back inside Rama. . . , I love you, Richard, never doubt it for a moment. I know it's unlikely, but maybe somehow, someday we will be united in another place. I promise you that if I survive to give birth to our child, I will never cease telling her about the intelligence, wit, and sensitivity of her father.

"I have one last request. If it turns out that either of you reaches home safely and I never return to the Earth, please explain to Genevieve what happened to me. Tell her the whole story, about the dream, the vial and the vision, and the Poro when I was a child. And tell her that I loved her with all my heart."

Tears were flowing down Nicole's cheeks when she finished her message. She stood up and rewound the tape. She played it for a minute, to make certain that it had recorded properly, and then walked over to the airlock. Goodness, she thought as she put on her helmet, I'm really going to do it During Nicole's eerie descent on the chairlift in the dark she had strong misgivings about her decision to return. It was only her supreme self-discipline that allowed her to chase away the lingering fears. As she climbed into the rover and started to drive toward the Cylindrical Sea, Nicole thought about how she would communicate with the intelligence governing Rama. /'// definitely use pictures, she said to herself, and wherever possible the precise language of science. That much I have learned from Richard.

The thought of Richard rekindled her anxieties. h.e.l.l think that I have abandoned him, she worried. And how can I really expect him to think otherwise? Nicole recalled the depressing first days of her pregnancy with Genevieve and how very lonely she had been having n.o.body with whom she could share her feelings. Again she felt a strong call to turn around and leave Rama. Her introspection was broken by the spectacular arrival of light. Dawn had come again to Rama. As before, Nicole was mesmerized by the sights around her. There's nothing like this anywhere in the universe.

When she reached what had been the Beta campsite, she first found and started to unpack the large sailboat. It was in good shape. It had been packed at the bottom of a large storage container. Working to a.s.semble the sailboat kept Nicole from brooding too much about her decision to leave the Newton. Mechanical a.s.sembly was not her forte. She almost despaired once when she had to disa.s.semble a major fitting that had taken her ten minutes to put together in the first place. The entire exercise reminded her of several frustrating Christmas Eves at Beauvois when she and Pierre had worked almost all night to put Genevieve's new toys together. "There ought to be a law that stores can only sell a.s.sembled toys," Nicole laughingly muttered as she struggled with the directions for the sailboat.

Nicole carried the hull of the boat down the steps and placed it right next to the water. Each of the major substructures she a.s.sembled on the cliff above, where the light was brighter. She was so engrossed in her work that she did not hear the footsteps until they were only two or three meters away. When Nicole, who was working on her knees, turned to her right and saw something approaching her from very close, she was frightened almost out of her wits.

Moments later she and Richard were kissing and hugging joyously. "O'Toole's coming too," he said, sitting down next to Nicole and immediately beginning to work on the sailboat.

"At first, when I explained that I wasn't leaving without you, that whatever life I could have on Earth wouldn't mean anything if you weren't with me, he told me that you and I were both crazy. But after we talked, and I explained to him that 1 thought we had a decent probability of warning the Ramans, he decided that he'd rather spend his last hours with us than take a chance on a lonely and painful death in the pod."

"But I thought you said that it would be a safe trip for a solitary pa.s.senger."

"It's not completely clear, The software loaded in the pod is a nightmare.

You can tell from the programming that it was done hastily. And how could it have been properly checked? O'Toole by himself might have had a better chance than the two of us together. . . But remember, he would face serious problems upon his arrival on Earth. That court-martial comment was not idle chatter."

"I don't think that Michael was afraid of a court-martial. He might have wanted to spare his family, but-"

A shout from the distance interrupted their conversation. General O'Toole was waving at them from an approaching rover. "But I don't understand," Nicole said. "How did he get here so quickly? You didn't walk, did you?"

Richard laughed. "Of course not. I left a beacon at the bottom of the chairlift After I arrived at Beta and saw that you had removed the sailboat and its parts, I sent the rover back on automatic."

"That was brave of you," Nicole said. "What if I had set sail during the extra time that it took you to find me on foot?" Richard peered over the cliff at the boat's hull down next to the water. "Actually you've done better than I expected," he said with a tease in his voice. "You might have finished in another hour or two."

He grabbed Nicole's hands as she tried to hit him. General O'Toole was the only practiced sailor among the three of them. Soon after they reached the midpoint of their sail, he relegated Richard to holding an oar as a possible weapon in case the pair of shark biots that were shadowing them decided to attack. "It's not Marblehead or the Cape/1 O'Toole said as he stared across at New York, "but it's definitely an interesting sail."

During the voyage Richard tried, without success, to convince a nervous Nicole that the shark biots were unlikely to bother them. "After all," he told her, "they didn't bother the boats at all during the first Rama expedition. They must have capsized me because of something special in the design of our new motorboats."

"How can you be so certain?" Nicole asked, staring uncomfortably at the gray shadows in the water beside them. "And if they are not going to attack us, why have they been following us for so long?"

"We're a curiosity, that's all," Richard replied. Nevertheless, he braced himself when one of the shadows suddenly veered toward the boat. It disappeared underneath them and joined its companion on the other side. "See," he said, releasing his grip on the oar, "I told you there was nothing to worry about."

They moored the sailboat on the New York side before climbing up the nearby stairway. Since General O'Toole had never been to New York before and was naturally very curious about what he was seeing, Richard went ahead to start working on the computer while Nicole gave the briefest of tours to O'Toole along the way.

By the time Nicole and the general reached the White Room, Richard already had some progress to report. "My hypothesis was correct," he said only seconds after the other two had joined him. "I'm fairly certain that I now have accessed the entire sensor list, They must have radar or its equivalent onboard. While I'm trying to locate it, why don't you two develop a flow diagram for how we will communicate our warning. Remember, keep it simple. We probably don't have more than twenty-four hours until the first missile arrives."

Twenty-four hours, Nicole said to herself. One more day. She glanced over at Richard, hard at work at the keyboard, and General O'Toole, who was looking at some of the black objects still scattered in one of the corners. Nicole's momentary feelings of fondness for the two men were quickly truncated by a sharp burst of fear. The reality of their predicament overpowered her. Will we all die tomorrow? she wondered.

61 ENDANGERED s.p.a.cECRAFT.

We really shouldn't be surprised," Richard said without emotion. The three of them were sitting in front of the large black screen. "AH of us expected it."

"But we hoped otherwise," O'Toole interjected. "Sometimes it's depressing to be proven correct."

"Are you positive, Richard," Nicole asked, "that each of those blips represents an object in s.p.a.ce?"

"I don't think there's any doubt," Richard replied. "We know for certain that we're looking at sensor output. And look, I'll show you how to change the fields." Richard called to the screen a display that showed a cylinder, definitely Rama, at the center of a set of concentric circles. Next he keyed in another pair of commands, resulting in motion on the screen. The cylinder became smaller and smaller, ultimately collapsing to a point. The size of the concentric circles around the cylinder also diminished during the motion and new circles appeared at the edge of the screen. Eventually a group of dots, sixteen in all, appeared on the right side of the display.

"But how do you know they are missiles?" Nicole queried, indicating the small points of light.

"I don't," Richard said. "But I do know they are flying objects nearly on a straight line between Rama and the Earth. I suppose they might be peace envoys, but I doubt it seriously."

"How long?" O'Toole asked.

"It's hard to tell exactly," Richard answered after a moment's pause. "I'd estimate eighteen to twenty hours until the first one. They're spread out more than I would have expected. If we track them for an hour or so, we'll have a more precise estimate of the impact time." General O'Toole whistled and then reflected for several seconds before speaking. "Before we try to tell this s.p.a.cecraft that it's about to undergo a nuclear attack, will you answer one simple question for me?"

"If I can," Richard replied, "What makes you think that Rama can protect itself from these incoming missiles, even if we are able to communicate the warning?"

There was a protracted silence. "Do you remember one time, Michael, almost a year ago," Richard said, "when we were flying together from London to Tokyo and we started talking about religion?"

"You mean when I was reading Eusebius?"

"I think so. You were telling me about the early history of Christianity. . . . Anyway, right in the middle of the discussion I suddenly asked you why you believed in G.o.d. Do you remember your answer?"

"Of course," O'Toole replied. "It's the same response I gave my oldest son when he declared himself an atheist at the age of eighteen."

"Your answer on the plane perfectly captures my att.i.tude in this current situation. We know that Rama is extremely advanced technologically. Certainly when it was designed there must have been some consideration of a possible hostile attack. . . . Who knows, maybe it even has a powerful propulsion system that we haven't yet discovered and will be able to maneuver out of the way. I bet-"

"Can I interrupt for a second?" Nicole said. "I wasn't with you two on the flight to Tokyo. I'd like to know how Michael answered your question."

The two men stared at each other for several seconds. Finally General O'Toole responded. "Faith informed by thought and observation," he said.

"The first part of your plan is not too difficult, and I agree with the approach, but I have no mental picture of how we will communicate the yield, or how to tie the nuclear chain reaction to the incoming missiles unambiguously."

"Michael and I will work on those items while you develop the graphics for the first segment. He says he remembers his nuclear physics reasonably well."

"Remember not to make too many a.s.sumptions," Richard reminded Nicole. "We must make certain that each part of the message is self-contained."

General O'Toole was not with Richard and Nicole at the moment. After two hours of intense work he had walked away, out into the tunnel, about five minutes earlier. His two colleagues suddenly worried about his absence. "He's probably going to the bathroom," Richard said.

"He might be lost," Nicole replied.

Richard moved over to the entrance to the White Room and hollered into the corridor. "Hullo, Michael O'Toole," he said.

"Are you all right?"

"Yes," came the answer from the direction of the central stairway. "Can you and Nicole come around here for a minute?"

"What's up?" Richard inquired a few moments later when he and Nicole joined the general at the foot of the stairway.

"Who built this lair?" O'Toole asked, his eyes focused on the ceiling high above him. "And why do you think it was created in the first place?"

"We don't know," Richard answered impatiently, "and I don't think we'll resolve the issue in the next few minutes, or even hours. Meanwhile, we have work-"

"Indulge me for a little while," O'Toole interrupted firmly. "I need to have this discussion before I can proceed." Richard and Nicole waited for him to continue. "We are rushing pellmell toward sending a warning to whatever intelligence is in control of this vehicle. Presumably, we are doing this so that Rama will be able to take measures to protect itself. How do we know that's the right action for us? How do we know that we're not being traitors to our species?"

General O'Toole waved his arms at the large cavern around him. "There must be some reason, some grand plan for all this. Why were all those fake human objects left in the White Room? Why did the Ramans invite us to communicate with them? Who and what are the avians and the octospiders?" He shook his head, frustrated by all the unanswered questions. "I was uncertain about destroying Rama; but I'm equally uncertain about sending the warning. What if Rama escapes the nuclear attack because of us and then destroys the Earth anyway?"

"That's extremely unlikely, Michael. The first Rama sailed through the solar system-"

"Just a minute, Nicole, if you don't mind," Richard interrupted softly. "Let me try to answer the general." He walked over and put his arm on General O'Toole's shoulder. "Michael," Richard said, "what has impressed me the most about you since the first time we met has been your ability to understand the difference between the answers we can know, as a result of deduction or the scientific method, and those questions for which there is not even a valid logical approach. There is no way whatsoever that we can understand what Rama is all about at this juncture. We don't yet have enough data. It's like trying to solve a system of simultaneous linear equations when there are many more variables than constraints. Multiple hypersurfaces of correct solutions exist."

O'Toole smiled and nodded his head. "What we do know/'

Richard continued, "is that a fleet of missiles is now approaching Rama. They are probably armed with nuclear warheads. We have a choice, to warn or not to warn, and we must make it based on the information available to us at this moment."

Richard pulled out his small computer and walked over beside O'Toole. "You can represent this entire problem as a three-by-two matrix," he said. "a.s.sume there are three possible descriptions of the Raman threat; never hostile, always hostile, and hostile only if attacked. Let these three situations represent the rows of the matrix. Now consider the decision facing us. We can either warn them, or choose not to. Note that it is only a successful warning that matters. So there are two columns to the matrix, Rama warned and Rama not warned."

O'Toole and Nicole both looked over Richard's shoulder as he constructed the matrix and displayed it on his small monitor. "If we now look at the outcomes of the six events represented by the individual elements in this matrix, and try to a.s.sign some probabilities wherever we can, we will have all the information we need to make our decision. Do you agree?"

General O'Toole nodded, impressed by how quickly and concisely Richard had structured their dilemma. "The outcome of the second row is always the same," Nicole now offered, "independent of whether or not we warn them. If Rama is truly hostile, with their more advanced technology it makes no difference whether we warn them or not. Sooner or later, with this vehicle or one that comes in the future, they will either subjugate or destroy the human race."

Richard paused a moment to ensure that O'Toole was following the conversation, "Similarly," he then said slowly, "if Rama is never hostile, it cannot be wrong to warn them. In neither case, warned or unwarned, is the Earth in danger. And if we are successful in telling them about the nuclear missiles, then something extraordinary will have been saved."

The general smiled. "So the only possible problem, O'Toole's Anxiety, if you want to call it that, comes if Rama was not originally intending to be hostile, but will change its mind and attack the Earth once it learns that nuclear missiles have been launched against it."

"Precisely," said Richard. "And I would argue that our warning itself would probably be a mitigating factor in that potentially hostile case. After all-"

"All right. AD right," O'Toole replied. "I see where you're headed. Unless a very high probability is a.s.signed to the case I'm worried about, the overall a.n.a.lysis suggests a better result from warning the Ramans." He suddenly laughed. "It's a good thing you don't work for COG military headquarters, Richard. You might have convinced me with logic to activate the code-"

"I doubt it," Nicole said. "n.o.body could have made a solid case for that kind of paranoia."

"Thank you." The general smiled. "I'm satisfied. You were very persuasive. Let's go back to work."

Driven by the relentless approach of the missiles, the threesome worked tirelessly for hours. Nicole and Michael O'Toole designed the warning message in two discrete segments. The first segment, much of which was background to establish the basic communication technique, presented all the trajectory mechanics, including the Rama orbit as the vehicle entered the solar system, the two Newton craft leaving the Earth and joining just before rendezvous with the alien ship, the two Raman maneuvers changing its trajectory, and finally the sixteen missiles blasting off from the Earth toward a Rama intercept. Richard, his long hours of work at the keyboard and black screen now paying off, transformed all these orbital events into graphic line drawings while the other two cosmonauts struggled with the complexity of the remainder of the message.

The second segment was exceedingly difficult to design. In it the humans wanted to explain that the incoming missiles carried nuclear warheads, that the explosive power of the bombs was generated by a chain reaction, and that the heat, shock, and radiation resulting from the explosion were all enormously powerful. Presenting the fundamental picture was not the challenge; quantifying the destructive power in any terms that could be understood by an extraterrestrial intelligence was a formidable obstacle.

"It's impossible," an exasperated Richard exclaimed when both O'Toole and Nicole insisted that the warning was not complete without some indication of the explosion temperature and the magnitude of the shock and radiation fields. "Why don't we just indicate the quant.i.ty of fissionable material in the process? They must be great at physics. They can compute the yield and other parameters." Time was running out and all three of them were becoming exhausted. In the final hours, General O'Toole succ.u.mbed to fatigue and, at Nicole's insistence, took a substantial nap. His biometry output had indicated that his heart was in stress. Richard even slept for ninety minutes. But Nicole never allowed herself the luxury of rest. She was determined to figure out some way to depict in pictures the destructive power of the weapons.

When the men awakened, Nicole convinced them to append to the second segment an additional short section demonstrating what would happen to a city or forest on Earth if a one-megaton nuclear bomb exploded in the vicinity. For these pictures to make any sense, of course, Richard had to expand his earlier glossary, in which he had defined the chemical elements and their symbols with mathematical precision, to include some more measures of size. "If they understand this," he grumbled as he laboriously included scale tick marks beside his line drawings of buildings and trees, "then they're smarter than even I gave them credit for."

Finally the message was completed and stored. They reviewed the entire warning one last time and made a few corrections. "Of the commands that I have never been able to understand/' Richard said, "there are five that I have reason to suspect may be links to a different level processor. Of course, I am only guessing, but I believe it's an educated guess. I will transmit our message five times, using each of these particular commands a single time, and hope that our warning somehow reaches the central computer."

While Richard entered all the proper commands into the keyboard, Nicole and General O'Toole went for a walk. They climbed up the stairway and wandered around the skysc.r.a.pers of New York. "You believe that we were meant to board Rama and find the White Room, don't you?"