"Well, we don't know, but we can speculate. For instance, about technologies based on quantum gravity.

Or even the manipulation of s.p.a.ce-time itself. If you could dothat there is no limit to what you could achieve. Warp drive-faster than light. Antigravity. The control of inertia-"

I began to see where this was going. "The San Jose Black Hole Kit would be a manipulation of s.p.a.ce- time."

"That toy black hole would have stood out like a single campfire shining in the middle of a darkened landscape."

"You think the San Jose people were trying to signal to aliens?"

"Oh, they didn'tmean to. All they were doing was trying to build a test bed for quantum gravity, just as advertised. I'm sure of that. But they wouldn't listen to our warnings-the Slan(t)ers. They would have gone on, and on, until they lit that d.a.m.n campfire . . ."

And then I understood what had been done. I rubbed my eyes. "What did you use, Peter?"

"Semtex-H," he whispered. "Not difficult to get hold of if you know how. Before the fall of communism the Czechs shipped out a thousand tons of the stuff, mostly through Libya. My police background . . ."

He hadn't set the thing off, he said, but he had designed the system. It turned out to be simple. He had used electronics parts he bought from RadioShack to build a simple radar-activated sensor. It was based on dashboard detectors supposed to warn drivers of the presence of a police radar gun. If attached to a detonator, such a sensor could be used to set off a bomb, in response to a signal from a radar gun-or even from something smaller, lighter. He had learned these techniques in Northern Ireland.

"You know, Semtex is remarkable. It's brown, like putty. You can mold it to any shape. And it's safe to handle. You can hold it over a naked flame and it won't explode, not without a detonator. So easy."

I held my breath.

"You see, it's all about the future," he said softly. "That's what I've come to understand. We humans find ourselves on a curve of exponential growth, doubling in numbers and capability, and doubling again. We are wolflings now, but we are growing. We will become adults, we will become strong.

Billions will flow from each of us, a torrent of minds, a great host of the future. This is our predestination. The future is ours. Andthat is what they perceive, I think."

"Who?"

"Those beyond the Earth. They see our potential. Our threat. They would want to stop it now, while we are still weak, cut down the great tree while it is still a sapling."

I tried to hold this extraordinary chain of logic in my head. "All right. I can see why you thought the San Jose lab should be stopped. But what are you doing here?"

"The hive is just as much of a threat to the future. Don't you see that yet? It is an end point to our destiny. And we have to avoid it."

I could see a glimmer of light in the rock cleft. He was holding something; it looked like a TV remote.

"Peter, what's that?"

"The switch," he said. "For the bomb."

My sister stood there in her white smock, her hands clenched in fists at her sides. I didn't need to tell Rosa her worst suspicions had turned out to be accurate.

Her attendants, the beefy drones, whispered and fluttered, wide-eyed, clutching each other and walking about in little knots. Meanwhile Peter sat silently in his cave, a brooding demon.

And I was stuck in the middle, trying to find a way out for everybody.

"Peter."

"I haven't gone anywhere," he said dryly.

"Do you trust me?"

"What?"

"I've listened to your theories. I've taken your advice. I've even taken you seriously. Who else has done all that?"

He hesitated. "All right. Yes, I trust you."

"Then listen to me. There has to be a way out of this."

"You're talking about negotiation? George-you said it yourself. You can't negotiate with an anthill."

"Nevertheless we have to try," I said. "There are a lot of lives at stake."

"n.o.body will be hurt. I'm not some homicidal nut, George, for G.o.d's sake. But I will open this place up. Expose it to the world."

"But maybe you won't even have to take the risk. Why not give it a try?" I fell silent and waited, forcing a response. Old management trick.

At last he replied. "All right. Since it's you."

I let out a breath I hadn't realized I was holding.

"Rosa,"he hissed now. "She is the key. The rest were born here, and are beyond hope. But Rosa might understand. She has a broader perspective, a self-awareness you're not supposed to have, here in the termite mound. You might persuade her tosee what she is. But George-you'll have to get her on her own. Get her away from the others. Otherwise you'll never jolt her out of it."

"I'll try."

I walked up to Rosa. Her eyes narrowed as she waited for me to speak. Suddenly I had power, I realized, but it wasn't a power I wanted. "He'll talk. But you have to do things my way, Rosa." I glanced at the drones, who continued to flap ineffectually behind her. "Get rid of these people."

Rosa actually quailed. I could see that the thought of being alone in a situation like this, cut off from the rest of the Order and the subtle cues of other drones, disturbed her on some deep level. But she complied. The drones went fluttering away, out of sight around the bend of the corridor.

I snapped: "And bring Lucia here."

She shook her head. "George, the doctors-"

"Just do it.And her baby. Otherwise I walk away."

We confronted each other. But, just as I had waited out Peter's response, I stared her down.

At last she backed off. "All right." She walked a little way down the corridor, dug a cell phone out of her pocket, and made a call.

It took a few minutes for Lucia to arrive. She was dressed in a plain smock, and she was carrying a small blanket-wrapped bundle. She was barefoot, and she walked slowly, uncertainly; I glimpsed attendants, perhaps from the chambers of themamme-nonne , lingering around the bend of the corridor. When Lucia saw me she ran toward me. "Mr. Poole-oh, Mr. Poole-"

"Are you all right?"

Her face was sallow, I saw, her cheeks sunken, her eyes rheumy. Her hair was coiffed but it looked lifeless. She had lost weight; I could see her shoulder blades protrude through the smock, and her wrists and ankles were skeletal. I would never have believed she was still just fifteen. But she was smiling, and she held up her baby to me-hersecond baby, I reminded myself. She handled the child awkwardly, though. "They had to fetch her from the nurseries . . . It's the first time I've seen her since she was born.

Isn't she beautiful?"

No more than a few weeks old, the baby had a small, crumpled face, and she was sleepy; but when she opened her eyes, they were mother-of-pearl gray. The baby seemed a little agitated: strange hands, my mother would have said. I felt sad for Lucia.

"Yes, she's beautiful."

She rubbed her stomach. "How is Daniel?"

"With his parents."

"I think of him often."

"What's wrong with your stomach? . . . Oh. You're pregnant again."

She shrugged and looked away.

I took her arm and found her a place to sit, on a bench carved out of the rock wall.

"Rosa, how did you get her out of the American Hospital?"

Rosa shrugged. "Do you really want the details? . . . The key was that she wanted to come out, despite everything she says. Didn't you, child?"

Lucia huddled over her baby, hiding her face.

Rosa said, "I've done what you asked, George. Can I talk to him now?"

"Go ahead."

She turned to the rock wall and raised her voice. "I don't know why you want to do this, Peter McLachlan. What harm have we done you-or anybody? We are an ancient religious order. We dedicate ourselves to the worship of G.o.d, through Mary, the mother of His son. We were founded for benevolent reasons. We educate. We store knowledge that would otherwise be lost. In times of trouble we act as a haven for vulnerable women . . . You can't deny any of this."

"Of course not," Peter said. "But you don't see yourself clearly. You can't, in fact; you're not supposed to. Rosa, even you, who were born outside, have been here too long. Your conscious purposes-the religion, your communal projects-are just by-products. No, more than that-they are glue to bind you together, dazzling concepts that distract your conscious minds. But they are not what the Order isfor .

They could be replaced by other goals-cruelty instead of benevolence, futility instead of useful purpose -and the Order would work just as well. The truth is the Order exists only for itself . . ."

In broken phrases he sketched his beliefs. The Order was an anthill, a mole rat colony, a termite mound, he told her. It was not a human society. "Your handful ofmamme-nonne , pumping out infants. Your sterile sisters-"

Rosa frowned. "Celibacy is common in Catholic orders."

"Not celibate.Sterile, " he hissed.

She listened to his arguments, her face working.

"And you can't argue with the reality of Lucia," he said. "Suppose she walked into a medical office in Manchester. The doctor would think Lucia was extraordinary-and so would you,if not for the fact that you grew up here. You have all been down in this hole for a long time. Time enough for adaptation, selection-evolution, Rosa."

Lucia looked up at me. "What's he saying? If I am not human, what am I?"

Rosa touched her hands. "Hush, child. It's all right . . ." She paced around, her heels clicking softly on the rock floor. I had no real idea what was going through her mind.

"Suppose it's true," she said suddenly. "It's hard to get my head around this nonsense-but suppose I concede that you're right. That we have formed a-a sort of self-organizing collective here. Even that, in some way, after all these centuries, we have somehow diverged from the common human stock."

"You're waking up," Peter said.

She snapped, "I don't think you are in any position to patronizeme . Let's remember that you are the nutcase stuck in a hole in the wall with Semtex stuck up his a.r.s.e."

"Go on, Rosa," I said quickly. "Suppose it's true. Then what?"

"Then-" She raised her hands, lifted her head to the levels hidden above us, the great underground city.

"If this is a new way, maybe it's a better way. We have found a way to run a society, safely and healthily, with population densitiesorders of magnitude higher than anything else humans have hit on.

What is the purpose of any human society? It is surely to provide a system in which as many people as possible can live out lives as long and healthy and happy and peaceful as possible. Wouldn't it be better for humankind, and this whole crowded planet, if everyone lived peaceably together as they do here?"

"Little drone, you know too much," he whispered.

She walked boldly up to the cleft. "Show your face, McLachlan."

He switched on his torch. His face, eerily underlit, hovered in the shadows, his expression unreadable.

Rosa said, "Suppose you're right. Suppose we are a new form-your word wasCoalescents ."

"Yes."

"Then shouldn't you accept us for what we are?" She spread her arms. "What have you found, here in this cave under the Appian Way? Aren't weh.o.m.o superior ?"

He clicked off his torch; his face disappeared into the dark.

Rosa had an intense expression, almost a look of triumph.

I asked, "Did you believe all that?"

She glanced at me. "Not a word. I just want him out of there." She was formidable indeed, I realized; I felt perversely proud.

Peter whispered again, from the dark. "George, she must have already figured some of this out for herself. Even if she didn't want to face it. I just put it into words for her.She knew it all the time. Really, she's too smart for the hive, for her own good."

"But she's listening," I said quickly. "Maybe we should take it easy. Don't do anything destructive.

We'll get the Order to open up, bring in the health professionals, the social workers . . ."

"There's no time for that," he said.

"Why not?"

"No time . . ." He fell silent, breathing heavily.

I tiptoed away. "I think he's tiring," I said to Rosa.

"Then," she said, "before he triggers his dead man's switch by falling asleep, I think you have a decision to make."

"Ihave a decision?"

"I can't say any more. But perhaps McLachlan will listen to you. You can encourage him to blow us all up. You can persuade him to walk away." Of course she was right, I saw, horrified; the decision had to be mine. "Just remember," she said coldly, "that there is a place for you here. Even now, even after you brought this lunatic into our Crypt. This can be your home, too. If you do anything to harm us,then you will lose that choice, too ."

I seemed to smell the pounds of Semtex Peter had lodged somewhere in the rock, sense the great weight of the subterranean city around me, the thousands of lives it contained.