Tessa called out their alt.i.tude, dropping rapidly at first, then slower and slower, until at six hundred feet they were only falling at twenty feet per second. Five seconds later she whispered, "Low gate," and Rick rocked the controller in his hand, switching out the computer.

He held his breath. This was when the previous two lunar modules had disappeared, at the point where the pilot had to take over. He waited for that to happen again, but the lander dropped another fifty feet, then seventy-five, and it was still there.

"Whew," he said. "We made it."

"What do you mean?" demanded Tessa. "We're still four hundred feet up!"

"Piece of cake," Rick said, looking out the window at the landscape slowly moving past. It was impossible to tell which little arc of crater rim was their target, and the tiny triangular windows were too small to give them an overview of the larger picture, so Rick just picked one that looked reasonably wide and brought the lander down toward it. It was strewn with boulders, but there were plenty of clear s.p.a.ces between them, if he could just hit one.

"Quant.i.ty light," Tessa called out. He had only a minute of fuel left, less than he was supposed to have at this alt.i.tude, but it was still plenty at their rate of fall.

He slowed their descent to ten feet per second and rotated them once around. One big boulder right on the rim had a wide flat spot beside it, so he angled over toward it. Flying the lander felt just like the simulator, save for the shifting of weight, and that actually helped him get a feel for the controls.

"Two hundred feet, eleven down," Tessa said.

Too fast. Rick throttled up the engine a bit.

"One eighty, six down. One seventy, three down. One sixty-five, zero down--we're going back up!"

"Sorry," Rick said, dropping the thrust again. While he was at it, he flipped on the sodium injector, and sure enough, the landscape exploded in bright yellow light. Even the bottoms of the craters were visible now, though they seemed fuzzy, out of focus.

No time to sightsee now, though. Tessa kept reading off the numbers, her voice rising a little in pitch. "Forty-five seconds. One sixty feet, four down. One fifty, five down; one forty, six down...you're picking up too much speed!"

"Got it," Rick said, nudging their thrust up a bit.

"One hundred, five down. Thirty seconds."

Rick did the math in his head. At this rate of descent he had ten seconds of fuel to spare. Far less than regulation, but still enough if he didn't waste any more. "Piece of cake," he said again, holding it steady for the spot he had chosen.

The descent went smoothly through the next fifty feet, but with only fifty feet to go, the ground began to grow indistinct. "What's that, are we kicking up dust?" Rick asked.

"I don't know," Tessa said. "It looks more like fog."

"Fog? d.a.m.n, Gregor was right." Rick held the controls steady, but they were descending into a white mist. The big boulder he'd been using for a marker disappeared in the cloud swirling up from the crater floor. Rick couldn't tell if they were still going to miss it or not; they could be drifting right over it for all he could tell.

Tessa's hand hovered near the Abort Stage b.u.t.ton. That would fire the ascent stage's engine, smashing the lower half of the lander into the surface as it blasted the top half free and back into orbit.

"We're too low for that," Rick said. "We'd crash with the descent stage if we tried it. Just hang on and call out the numbers."

"Roger. Twenty, five down."

That was pretty fast, but Rick didn't budge the controller. If he shifted them sideways in the process, they could hit the boulder.

"Fifteen...ten...contact light!"

The feelers at the ends of the landing legs had touched the surface. Rick let the engine run for another half second, then shut it down. The lander rocked sideways just a bit, then lurched as they hit the surface hard. "Engine off,"

Rick said, his eyes glued to the ascent engine fuel level. It held steady. No leaks, then, from the shaking, and no warning lights on any other systems.

Looking over at the descent engine's fuel gauge, he saw that they had six seconds left.

Tessa glared at him. "Piece of cake?" she asked. "Piece of cake?"

Rick, at a loss for words, could only shrug.

Yoshiko's voice came over the radio. "Faith, Are you down?"

Tessa laughed. "Yes, we're down. Through fog as thick as soup, with six seconds of fuel left."

Fog. There was water on the moon. Rick looked out the window, pointed. "Look, it's blowing away."

Without the rocket exhaust and the harsh sodium light to heat the ice in the crater floor, what had already vaporized was rapidly expanding into the vacuum, revealing the rubble-strewn crater rim on which the lander had touched down.

Rick looked for his landmark boulder, saw it out of the corner of his window, only a few feet away from the side of the lander. They had barely missed it. In fact two of the legs had straddled it. If one of them had hit it the lander would have tipped over.

Rick put it out of his mind. They were down, and they had more important things to worry about.

Time seemed to telescope on them as they ran through another checklist to make sure the ascent stage was ready to go in an emergency, then they depressurized the lander and popped open the hatch to go outside. Rick went first, not because it was his Apollo or because he was in any way more deserving, but for the same reason that Neil Armstrong went first on Apollo 11: because in their bulky s.p.a.cesuits it was too difficult for the person on the right to sidle past the person on the left in order to reach the door.

It was a tight squeeze, but he made it through the hatch. The corrugated egress platform and ladder were in shadow, so Rick had to climb down by feel. He pulled the D-ring that lowered the outside camera, and Gregor radioed that they were receiving its signal back on Earth. Rick figured he was probably just a silhouette against the side-lit background, but he supposed that was about as good as the grainy picture of Neil taking his first step.

He was on the last rung when he realized he hadn't thought up anything historic to say. He paused for a moment, thinking fast, then stepped off onto the landing pad and then from there onto the frozen lunar soil. It crunched beneath his feet; he could feel it, though he couldn't hear it in the vacuum.

Tessa had made it through the hatch, too, and was watching from the platform, obviously waiting for him to speak, so he held his hand up toward her--and symbolically toward Earth, he hoped--and said, "Come on out. The water's fine!"

The water was indeed fine. Fine as powdered sugar, and about the same consistency. Brought to the Moon's surface in thousands of comet strikes over the millennia, it had acc.u.mulated molecule by molecule as the vaporized water and methane and other ga.s.ses froze out in the shadowed crater bottoms at the poles. It was too cold, and the Moon's gravity was too light, for it to pack down into solid ice, so it remained fluffy, like extremely fine snow. When Rick and Tessa walked out into it they sank clear to their thighs, even though they only weighed about fifty pounds, and they would probably have sunk further if they'd gone on. But they could feel the cold seeping into their legs already, so they had to scoop up what samples they could in special thermos bottles designed for the purpose and turn back. The sample equipment packed in the lander was designed for a polar mission, but their s.p.a.cesuits were made to keep them warm in vacuum, not against ice that could conduct heat away.

So they walked around the crater rim, bounding along in the peculiar kangaroo-hop gait that worked so well in light gravity, looking for anything else that might prove interesting. That was just about everything as far as Rick was concerned. He was on the Moon! Every aspect of it, from the rocky, cratered ground underfoot to the sharp, rugged horizon, reminded him that he was walking on another world. He looked out toward the Earth, about two-thirds of it visible above the horizon, about two-thirds of that lit by the sun, and he felt a shiver run down his spine at the sight. He had thought he would never see it like that except in thirty-year-old pictures.

They were making pictures of their own now. Tessa carried the TV camera and gave a running commentary as they explored. Gregor said that everyone in Russia and Europe was watching, and Tomiichi said the same for j.a.pan. And surprisingly, Laura said the same about the United States. "They even pre-empted Days of Our Lives for you," she told them.

"Hah. Maybe there's hope for our country yet," Rick muttered.

"Watch it," Tessa said, but whether for fear of him offending their watchers or for fear of him getting too hopeful she didn't say.

Rick didn't care. He felt an incredible sense of well-being that had nothing at all to do with whether or not they made it back alive. They were on the Moon, he and Tessa, at the absolute pinnacle of achievement for an astronaut. Higher than anything either of them had ever expected to achieve, at any rate. No matter what they faced on the way home, or after they got there, nothing could alter the fact that they were here now. And Rick couldn't think of anyone he would rather share the experience with. He and Tessa would be spoken of in the same breath forever, and that was fine with him. He watched the way she bounded along in the low gravity, listened to her exclaim with delight with each new wonder she discovered, and he smiled. He wouldn't mind at all sharing a page in the history books with her.

They collected rocks and more ice from all along their path. At one stop Rick packed a handful of snow into a loose ball and flung it at Tessa, who leaped nearly five feet into the air to avoid it. When the s...o...b..ll hit on the sunlit side of the crater, it burst into a puff of steam.

"Wow," Tessa said as she bounced to a stop, "did you see that? Do it again."

Rick obligingly threw another s...o...b..ll past her, and she followed it with the camera until it exploded against a rock.

"Did you guys back home see it too?" she asked. "What makes them blow up like that?"

Gregor said, "Heat, I'd guess. And vacuum. Without an atmosphere to attenuate the sunlight, a rock will heat up just as much there at the pole as it would at the equator, so when the snow touches the hot rock it flashes into steam."

"Hah, I suppose so. Looks pretty wild."

"It might also give us a good idea what ga.s.ses are in the snow. Rick, could you set a sample down a bit more gently on a sunlit surface and let us see how it boils off?"

Rick did as he asked, packing a double-handful of snow and setting it on a boulder's slanted face. Steam immediately began to rise from it, then stopped after a few seconds. The s...o...b..ll shifted slightly and more steam sublimed off, then another few seconds pa.s.sed before the remaining snow melted into a bubbling puddle.

"Aha!" Gregor said. "Three separate fractions, at least. I would guess methane for the first, then ammonia or carbon dioxide, and finally water. That is wonderful news! All four ga.s.ses will be useful to a colony."

"If we ever send one," Rick said, trying to suppress his silly grin so Tessa wouldn't grow afraid of his optimism, but that in itself made him laugh out loud.

"d.a.m.n it, Rick, you're scaring me half to death!" she said. They both turned to look at the lander, glittering like a gold and silver sculpture on the concrete gray crater rim, but it remained solid.

"Don't worry," Rick told her. "I may be having fun, but I'm still just as scared as you are."

"Good."

They explored for another hour, but before they had even made it a tenth of the way around the crater they had to turn back. The suits only held another two hours of oxygen, and they would need that time to return to the lander, climb back inside, and pressurize the cabin again. And after that their time on the Moon would be over, because they had to get back to Hope as quickly as possible and blast off for Earth again before the plane of their polar orbit shifted too far away from a return path. Their SPS engine had enough fuel for a plane change of a few degrees, but the longer they waited the more it would take.

They had done enough already. They had discovered water on the Moon, and had gone a long ways toward proving that it could sustain a colony if humanity wanted to send one. Now all they had to do was get home alive, but that in itself was a big enough job to keep them occupied full-time.

Yet as he waited for Tessa to climb up the ladder and kick the dust from her boots, Rick thought of one more thing he could do. His heart leaped in his throat at the thought, but it would be the perfect cap to a perfect day--provided he really wanted to do it. And provided he'd read Tessa's signals right as well.

He had no time to decide. It was now or never. He gulped, muttered, "He who hesitates is lost," and moved back away from the lander.

"What?" Tessa asked. She had reached the egress platform.

"Don't go inside yet." Rick paced a few yards away, then began scuffing five-foot-high letters into the crunchy soil with his boot. They showed up beautifully in the low-angled light.

"What are you doing?" she asked him.

He didn't answer. It would become obvious in a moment, if he could just remember how to spell. That was no sure bet; his head buzzed like an alarm going off, and his breath came in ragged gasps that had nothing to do with the exertion of drawing in the dirt. This would change his life even more than the trip to the Moon. Maybe.

"Oh, Rick," Tessa said when he completed the first line, but she grew silent when she saw him begin a second. She was still silent when he finished his message: Tessa, I love you.

Will you marry me?

He was still standing on the final dot below the question mark. He looked up at her, a dark silhouette against the darker sky, her gold-mirrored faceplate reflecting his own sunlit form and the words he'd written. He couldn't see her expression through it, couldn't tell what she was thinking. He waited for some indication, but after the silence stretched on so long that Gregor asked, "Rick?

Tessa? Are you okay?" she began to climb down the ladder again.

"Stand by, Kaliningrad," Rick said.

Tessa stepped back onto the lunar surface, walked slowly and deliberately over to stand beside Rick. Even this close, he couldn't see her face, but he heard her sniff.

"Tess?"

She didn't answer him, at least not over the radio. But she shook her head a little and stepped to the side far enough to scratch a single word in the soil: Yes.

Rick echoed it aloud. "Yes!" All his apprehension died in an instant. He bounded over to her and wrapped her in a bear hug. "Tessa, I love you!"

"Oh, Rick."

"Are you two getting mushy again?" Yoshiko asked.

Rick laughed. "Mushy, h.e.l.l, we're getting married."

The radio burst into a jumble of voices as everyone spoke at once, then Gregor's voice cut through the rest. "My sincere congratulations," he said, "but your launch window is fast approaching."

"Roger," Rick said. "We're going inside now."

He helped Tessa climb back into the lander, then he climbed up and kicked off as much dust as he could. Before he ducked in through the hatch he looked down at the words they had written on the ground, their declaration clearly written for all to see. Those words could stay there for a billion years or so, the way things weathered on the Moon. Or if people actually came up and mined the crater for ice, they could be obliterated within a decade. That would depend quite a bit on what happened on the trip home.

Rick thought again of all the things that could yet go wrong. Engine failures, docking failures, computer failures--the list seemed endless. Despite his excitement over his and Tessa's future, if their personal welfare over the next few days made any difference then he would have no trouble staying sufficiently pessimistic to keep the ghost from fading away on them.

The number of possible disasters shrank with each stage of the mission: Faith's ascent engine carried them into orbit, and Yoshiko docked smoothly with the lander, and the SPS engine fired on time to send them back homeward; but the way Rick figured it, infinity minus a few was still infinity. Plenty of things could still go wrong.

Including, of course, the ghost disappearing. Twice more on the return trip, both times right after Gregor reported that "Moon fever" was once more gripping the world, the s.p.a.cecraft's walls grew indistinct around them, and both times they came back only after Rick convinced himself that their deaths could still squelch humanity's renewed enthusiasm for s.p.a.ce. All the evidence seemed to support Yoshiko's and Tessa's theory that he was somehow in control of the apparition, whether or not he was directly responsible for it.

Gregor would say no more about it, save that he should listen to them. Tessa took that as carte blanche to control his every action, including sleep, which she wouldn't let him do. She was afraid he would start dreaming of the bold new age of s.p.a.ce exploration and they would all die of explosive decompression before he could wake up. She refused to let Gregor or Tomiichi or Laura tell them anything about the situation on Earth, and she kept inventing elaborate new scenarios in which humanity would decide not to follow their lead after all. And now that they were engaged, she seemed to think Rick's personal s.p.a.ce was hers to invade in whatever imagininative ways she could think of as well. She would tickle him if she thought he was drifting off, or kiss him, or brush against him seductively. Rick found it alternately amusing and annoying, depending on which stage of his sleep deprivation cycle he was in at the time.

To keep himself busy, and to keep his mind on other things, he made her an engagement ring out of one of the switch guards, which were already nearly the right size and shape. He snapped one off from beside a third-stage booster control that didn't connect to anything anymore, and with a little filing on a zipper he buffed the rough edges down enough for her to wear it.

"I'll treasure it forever," she told him when he slid it onto her finger, but Rick was too befuddled from lack of sleep to know if she was fooling or serious.

Finally, less than a day out from Earth, Tessa could no longer stay awake either. As she drifted off to sleep, she admonished Yoshiko to continue the job, but as soon as her breathing slowed, Yoshiko told Rick, "Go ahead and sleep if you want. I think you'll be more valuable to us tomorrow if you get some rest now."

Rick, groggy with fatigue, tried to focus on her face. "Why?" he asked. "What's tomorrow?"

She grinned diabolically. "Re-entry. Twenty-five thousand miles an hour, smack into the atmosphere. Sleep well."

Rick slept, but just as Yoshiko had intended, all his dreams were of burning up in a fireball as the Apollo capsule hit the atmosphere at too steep an angle, or of skipping off into interplanetary s.p.a.ce if they hit too shallow. Or of hitting their window square on and still burning up when the ghost ship proved incapable of withstanding the heat. The gunpowdery smell of the lunar dust they had tracked inside on their s.p.a.cesuits didn't help any, either; it only provided another sensory cue that they were on fire.

When he woke, Earth was only a couple hours away. It still looked much smaller than it had from the shuttle, but it felt so much closer and it looked so inviting after his hours of bad dreams that Rick almost felt like he was home already.

With that thought, the capsule grew indistinct again. Tessa screamed, "Rick!"

and punched him in the chest, and Yoshiko said quickly, "Remember the consequences!"

The ship solidified once more, and Rick rubbed his sore sternum where Tessa's ring had jabbed him. "Jeez, you don't have to kill me," he said. "I get scared just fine on my own when that happens."

Tessa snorted. "Hah. If you were as scared as I am the ship would never disappear in the first place."

"Well I'm sorry; I'll try to be more terrified from now on." Rick turned away from her, but there was no place to go to be alone in an Apollo capsule. After a few minutes of silence, he looked back over at her and said, "Okay, I'll try harder to control this. But don't look at me so accusingly when it happens, okay? I'm not trying to make it disappear."

Tessa sighed. "I know you're not. It's just--I don't know. I don't have any control over it, except what little control I have over you. My life is in your hands. h.e.l.l, at this point the entire s.p.a.ce program is in your hands. And all you have to do to kill it is get c.o.c.ky."