At last the bus doors slid closed. Maura waited for the soft clunk of the docking tunnel disconnecting from the hull of the bus, and then came the jolt as the bus pulled away and drove itself off through the Moon’s marshmallow gravity.

The sun was high, and unfiltered light, harsh and static, flooded down into the complex canyons and crevasses of the brutally folded surface of Tycho.

Bill was shaking, sweat clustering on his forehead in great low-G beads. She got up and brought him a plastic cup of water. Slowly he calmed down. For now they were safe. You couldn’t mount a car chase through this ancient, hazardous maze of canyons. Besides, the military presence on the Moon remained small; she doubted the commanders would risk any kind of surface operation to intercept them en route to Never-Never Land.

Anyway there was no need. All that was necessary was to wait until Maura and Bill arrived at Never-Never Land and take them out then; there was, after all, no other place to go.

Well, she would deal with that eventuality when it came.

Bill pointed upward. “Look.”

A star was crossing the sky with ponderous slowness. It seemed to be sparkling, pulsing with light with slow regularity. It was, of course, artificial: a satellite, slowly rotating, new, bigger than anything she had seen before. She had absolutely no idea what its purpose might be.

She found herself shivering, and she clutched Bill’s arm.

Strange lights in the sky, she thought. Scary. Even if we put them there.

Especially if we put them there.

It proved easier, oddly, to get into Never-Never Land than to get out of the NASA base. The troopers here seemed to be operating under radio silence. And besides, as Maura herself was quick to point out, once they were inside Never-Never Land they were effectively under house arrest anyhow. What were they going to do, climb out of a window?

So she was admitted. Bill had to wait in the bus.

At first glance nothing had changed here. The dome glowed its daytime sky blue, sun and Earth hung there like lanterns, and the grass was a livid green, almost shocking to the senses after the gray of the Moon. But nevertheless Maura sensed there was something wrong. The air seemed chill, and she saw the leaves of the fat, squat oak tree rustle. From somewhere there came an odd cry, perhaps human, perhaps animal.

At the airlock’s inner door was the bulky blond German trooper whom Maura had come to know — and to dislike intensely — during her visits here. He was fingering the revolver at his waist. Anna stood before him, talking earnestly. Her wings were on the ground behind her. There were no other children in sight.

Anna hurried to Maura. “You have to help me. I’m trying to make him understand.”

Maura held Anna’s arms. “What do we have to understand?”

“What is to come.”

Maura’s skin prickled.

Maura glanced at the trooper. He was staring at Anna. Leering, Maura thought uneasily, leering without speaking.

Anna led her away, deeper into the dome across the grass, talking intently. It came out of Anna in broken fragments, scraps of speech. Occasionally the girl would lapse into metalanguage: shards of song, a few clumsy dance steps. “The arrow of time,” she said. “Inner time. Do you understand? This is the key. If you close your eyes you feel time. You feel yourself enduring. Time is essential to awareness, where space is not, and so is more fundamental. The flow of time, events happening, the future coming into existence.”

“Yes.”

“But you don’t understand time. Your scientists use time as a coordinate, a label. You even have theories that are time-symmetric, that work whether you run them forward or back in time.” The girl actually laughed at that.

“And that’s wrong?”

“Of course it’s wrong. It is trivially wrong. There is a severe discrepancy between your theories and what you feel is the reality of the world. And that is telling you, should be telling you, something quite fundamental about the physics that actually underlies your conscious processes.”

“All right. Tell me about the arrow of time.”

Anna danced, whirled, her dress lifting; and Maura was uncomfortably aware of the soldier’s eyes. “There are an infinite number of possible universes in the manifold,” Anna said. “Of those only a subset — nevertheless infinite itself — are capable of supporting self-aware substructures. And those universes are characterized by a flow of time, which is created by unfolding cosmic structure. Gravity is the key.”

Maura was getting lost again. “Gravity?”

“A universe with gravity is driven from smoothness to dumpiness because of gravitational collapse. And the arrow of time comes from this flow of matter and energy, from the gravitational arrangement of the universe at its beginning, to the equilibrium state at its end. Life depends on a flow of energy and information, to be dammed and used. So the arrow of time, like perception itself, is intimately linked to the structure of the universe.”

“Go on.”

Anna was still talking, still dancing. “But structure and change are not restricted to a single universe. They span the manifold of evolving universes. And so, therefore, does life. Do you see?”

“No.”

“When this universe was spawned from the previous generation, it went through a series of phases. That is, the vacuum did.” Anna was watching her, seeking signs of understanding. “The vacuum is a complex thing. Space can be bent by gravity, but it resists with a strength far stronger than steel. The vacuum is a sea of energy, of virtual particles that pop in and out of existence.”

“All right,” Maura said, struggling to keep up.

“But it is possible for the vacuum to take different phases. Think of water. Liquid water may achieve a higher energy phase — it may flash to steam — or it may seek a lower energy phase—”

“By freezing, forming ice.”

“Yes. Systems lose energy, tend to seek the lowest energy state.”

“I understand. And so the vacuum—”

“After the Big Bang the vacuum itself descended through a series of energy states. This is the most primitive unfolding of all, the source of the time river, the source of life and mind.”

“Until it settled on the lowest, umm, energy state. Which is our vacuum. Right?”

Anna frowned. ‘Wo. Our vacuum is only metastable. It is not in the lowest level, not even now. This began in the Big Bang and continues now. But it needs, umm, help.”

“Help? What kind of help?”

The girl grabbed her hands. “You must see what this means. The evolution of the vacuum is a flow of information. But this is a flow that spans the manifold itself, and is therefore fundamental.” Anna’s eyes searched Maura’s. “Life spans the manifold. The vacuum metastability makes you what you are. This is the reason for what we are doing. And this is what you must tell them.”

“Who?”

“The people.” She waved a hand at the soldier, vaguely in the direction of Earth. “Make them understand this.”

“What for?”

“Consolation.”

“My God, Anna—”

And then, it seemed, time ran out for them all.

It was as if a cloud had passed over the sun.

Anna licked a finger and raised her hand. “There’s no breeze,” she said. “They turned the systems off.”

Maura looked up. The dome had darkened. She could see the sun, just, a diffuse distorted disc, shedding no meaningful light. Perhaps the polarization had been switched to its night setting.

Artificial lights sparked, flooding the dome with a cold fluorescent glow, a deadness that contrasted powerfully with the living green warmth of a moment ago.

The German trooper touched Maura’s elbow. She heard the insect whisper of a speaker in his ear. “We have to get you out of here, ma’am.” He was pulling at her, firmly but gently, separating her from Anna; Maura, bewildered, let it happen.