Climbing back up to the cockpit, they found Eddie working on the mass amplifier with a small soldering iron. It was sitting on his chair with the lid open and a small curl of smoke was rising from where he was working. “You'll find the secondary navigation system's not working,” he said without looking up. “I had to borrow some bits from it.”

“Did you check that the primary system was working before you did that?” asked Benny.

“Not being a total moron, I did. If it hadn't been, I'd have taken the chip from it instead.”

Benny took his seat to run a diagnostic program anyway while Paul went over to stand beside Susan. “You okay?” he asked, putting a gloved hand on the shoulder of her spacesuit. It was meant to be comforting and reassuring, but he doubted that she even felt it through so many layers of fabric.

“Fine,” she replied. “I enjoy being tied to chairs.” She regretted her sarcastic words as soon as they were out of her mouth, since they would inevitably draw his attention to the zip ties around her arms. If he should notice that one of them was considerably lower on her arm than it had been...

He apparently didn't notice, though. “I know that what happened wasn't your fault,” he said. “You were under a lot of stress, you didn't know what you were doing...”

“Er, actually, I'm pretty sure she did,” and Eddie, though. “We were talking while you were outside and she didn't sound at all remorseful.”

“You don’t know her like we do,” said Paul, though. “We’ve spent months on the space station together, you get to know someone pretty well under those circumstances. If she were in her right mind, she just wouldn't be capable of such a thing! Only a few hours have passed, it probably takes longer than that for someone to recover from something like that. By the time we get back to Harmony I'm sure she'll be back to her old self and we’ll all be laughing about it.” Eddie nodded doubtfully. “Even so, though,” said Paul to Susan, “I'm afraid you’ll have to stay tied up for a little while longer. As soon as we're safely on our way back home we can let you loose. Just an hour or so, probably.”

He looked over at Eddie, who nodded. “Yes, I'm pretty much done here,” he said. “Of course, we won't know if it’s actually working until we turn it on, but I've fixed all the visible damage. If it still doesn't work, I have no idea where the problem might be, and It’ll probably take more time than we have to find out.”

“Then let’s hope it's working,” said Paul.

“How much time do we have, by the way?”

Paul looked at the clock display on the inside of his visor. “If the estimate they gave us is accurate, we’ve got an hour before the river of magma arrives. Of course, it may arrive early, or late...”

“How soon before we can lift off?” asked Benny.

“Just give me five minutes to finish up,” said Eddie.

“Any way you can hurry it up?”

“If we were seconds away from being immolated, probably, but I'd rather take my time if I can.” Benny nodded reluctantly and went to the windows, trying to remember from what direction the magma would be coming. That way wasn't It? He looked to the west, but there was nothing visible on the horizon but flashes of lightning, vividly bright against a dark backdrop. The view was blurry, and when he looked closer he saw that the outside of the windows were being sandblasted by the dust, just as the visor of his helmet was. His eyes had adjusted to the scouring of his visor so that he no longer noticed it, but now he was seeing the moon through two layers of frosted glass. Still, he ought to be able to see a river of magma if there was one out there...

There was a faint brightness in the distance, he saw. He hadn't noticed it at first, it was partially obscured by sheets of dust being blown on the wind. It was right at the edge of perception. Was he imagining it? He stared at it, trying to force his brain to tell him if it was real, and at that moment the shuttle was shaken by another moonquake, the most violent one so far. The three astronauts braced themselves, and Eddie hastily withdrew the soldering iron from the machine’s interior before the hot tip touched the wrong thing and caused irreparable damage. From under the floor came the sound of something falling over in the room below, the crash and clatter of metal.

The ground heaved under them and the shuttle was thrown like a cowboy riding a steer. The astronauts were briefly weightless, and then the shuttle hit the ground again with a slam that made Paul fear that it might have suffered fatal damage. He heard the sound of glass shattering and looked up in time to see the front window falling in jagged shards into the cockpit. The wind blew in, carrying moon dust that swirled around them and got everywhere. Eddie closed the case of the mass amplifier with a cry of alarm. “Keep the dust out!” he cried. “Dust will wreck the machine!”

Paul stared at the jagged hole in the window, wondering what they had that they could possibly cover it with. “Take it below,” he said as the shaking continued. “We can block the hole in the floor easier than the window.” Eddie nodded, but waited to pick the device up until the vibrations began to subside. Then, the device in one hand and the soldering iron in the other, he staggered across to the ladder. He tucked the soldering iron under his arm, making sure the hot tip wasn't touching his spacesuit, then climbed down the ladder one handed.

Paul looked around for something to block the stairwell with, then just climbed half way down the stairs so that his spacesuited body was doing the job. Benny, meanwhile, picked to every piece of broken glass he could find and threw them out through the broken window. There was dust settling on the flight controls. He tried to brush it away but more just blew in to replace it. The display screens were hidden by it, and it would prevent the glass surface from being able to detect the touch of his fingers. “We can't fly like this!” he cried in dismay.

Susan chuckled. “Man proposes,” she said. “God disposes.”

“I'm the captain of this ship!” said Paul, though. “Not God.” He turned to Benny. “The moment we turn on the mass dampener, the wind will stop,” he said. “Or at least, it’ll blow upwards, not horizontally. Will you have time to clean the displays off before we have to start the engines?”

“If I had a brush, perhaps. I daren't just use my hands, I'll scratch the screens. Wait a minute... Where's the vacuum cleaner?”

“Down below,” said Paul, “but there's too much dust to suck up.”

“Not suck, blow. We can blow the dust off. Eddie, can you hand the vacuum up?”

“Little busy at the moment,” replied Eddie over the intercom.

“Soon as you can, then.” He looked out the window again, towards where he'd seen the glow a moment before. Perhaps he'd only imagined it...

The glow was still there, and brighter than before. A dull red glow that lit the underside of the thick clouds covering the sky. “Skit!” he cried in alarm. “The magma! It's almost here!”

Paul joined him and looked in the same direction. Even through the thick spacesuit, Benny saw him stiffen with fear. “Eddie!” he cried. “We need that mass amplifier. Now!”

“And the vacuum cleaner," added Benny.

“I'm almost done...”

“The magma river's almost here! We can see it coming! We need that thing now!”

They heard a curse over the intercom and the sounds of the frantic clattering of small, metal objects. “Ten seconds!” he cried.

“Make it five. In fact, make it now! Right now!”

The glow was getting brighter even as they watched, and then they saw the magma itself, splashing and running across the dusty plain towards them seemingly as fast as an express train. “I’ve seen magma” said Paul in disbelief. “I was on Mt Etna in fifty five. It was slow. A snail could have kept in front of it.”

“We can ask the vulcanologists later,” said Benny. “Right now I estimate we have about sixty seconds before...”

”Ready!” called Eddy over the intercom. “Let me know when to turn it on.”

“Where’s the bloody vacuum?” cried Benny.

“Oh! Yes! Er, where is it?”

“Beside the airlock door. Next to the fire extinguisher. Hurry!”

A moment later Paul reached down, lifted up a small, compact object and handed it to Benny. He flipped a switch on the side, flipped another and a gust of air blew from the nozzle at the front. He used it to blow the dust from the instrument panel and the display screens. “Here,” he said to Paul, handing it across to him. “Keep blowing dust. I'm going to start everything up.” Paul took it and kept working to keep the cockpit clean. The air was full of dust now, making it hard to see what they were doing. Most of the dust he blew off just settled somewhere equally inconvenient, but he kept at it and watched as the display screens lit up with status reports and system indicators. Eddie reappeared through the stairwell and took his place beside Susan in one of the rear seats. He'd closed the case of the mass amplifier and stuck some tape over the holes to keep the dust out. “Let me know when to turn it on,” he said.

“All systems show ready,” said Benny. “Are we good to lift, Paul?”

“You're in charge,” Paul replied. “You’re in command when we’re under way.”

“Understood. I'm in command. “Eddie, switch on in five. Understood?”

“Understood.”

“Five, four, three, two, one...”

Orbiting the moon, the mass dampener aboard Lunar Rescue One activated, rendering the entire moon and the shuttle virtually massless. A fraction of a second later Eddie's mass amplifier activated, restoring mass to the shuttle and its remaining fuel. Without weight to hold it down, the entire moon then expanded outward. Its atmosphere shot upwards and the magma ocean leapt into the sky. Eddie felt a gentle pressure pushing him down into his seat as the moon's solid remnant was pushed towards by the pressure of the magma below. Benny saw the magma river recede, leaving behind rock that had been heated red by its brief presence. The wind that had been gusting in through the broken window fell still and the dust settled, leaving the air thankfully clear.

The crew settled down in their seats and waited for the initial acceleration to stop.

☆☆☆

Down on Earth, millions of people glued to their television screens for any news of the mission, or standing outside staring up at the moon in the sky, gave a collective gasp as they saw it ballooning outwards, just as it had during the ill fated Chinese attempt to protect the world. Richard Lewis yelled for his mother to wake up and come out to see the scenes unfolding on their small tablet screen. Margaret shot out of the bedroom she shared with Cathy and Hazel, the two younger woman hurrying to keep up with her as she rubbed the sleep from her eyes. She had tried hard to stay awake for the entire duration of her husband's mission, but fatigue had caught up with her and she had finally been persuaded to go and lie down, after having made her son promise to wake her up if anything happened.

“...the sign we've all been waiting for,” the invisible commentator was saying. “We can deduce now that the crew of the Pluivier survived their hazardous landing on the surface of the moon and have tethered the shuttle to it. Now begins the task of pulling it back into its old orbit.”

Margaret breathed a huge sign of relief, while outside they heard distant sounds of cheering from the men of the airbase. Someone, somewhere, had begun setting off fireworks, a little prematurely, Richard thought. On the screen, the moon, which had been nothing more than a featureless, steely grey disc, was suddenly bisected by a line of incandescent brightness where superheated magma was escaping from under the edge of the remaining rocky crust. People out in the open, staring up at the moon in the night sky, suddenly had to shade their eyes and look away as if they were looking at the sun. Margaret gasped in horror, thinking of Paul being so close to that vast release of energy, but she knew that the solid crust to which the shuttle was tethered was shielding him from it. The commentators on the television had taken pains to explain that over and over again over the previous few hours.

“I know there's a chance he might not have survived,” she said, “but at least one of them must have, and that means there's a good chance that he did.” She gathered Richard and Hazel up in her arms and gave them a hug. “He's coming back to us!” she said. “I know it!”

“Course he is,” agreed Richard, hoping it was true. Watching the agonies his mother had been going through had been almost as bad as his own anxiety about the safety of his father. “He's coming back. I have a good feeling about it.”

Margaret replied by tightening her hug about him. Richard wondered whether he ought to say something to reflect the fact that Paul was far from out of danger yet, in case her hopes were raised too high and the news of a tragedy was consequently more devastating than it would otherwise have been, but there was nothing he could tell her that she didn't already know. He kept silent, therefore, deciding that what she needed now were words of hope and optimism. Bad news might come later, but right now there was hope and that was what she needed.

“He's coming home,” he said again, therefore. “Think of the party we're going to have when he gets here, when he comes in through that door.”

Margaret nodded, and they stared at the image of the exploding moon on the small tablet screen as the commentator waffled on about the challenges the crew of the Pluvier would be facing next. Len and Cathy, meanwhile, knowing that, much though they and their spouses loved each other, this was a moment in which they couldn't fully share, went to the kitchen area to make them all a nice cup of tea.

☆☆☆

Benny waited impatiently for the initial upwards acceleration to stop. As the curving, two thousand kilometre wide section of lunar crust rose, the magma below found itself free to escape sideways from under it and the upwards pressure lessened. The acceleration dropped off, therefore, and the crew found themselves in free fall. Benny tapped out commands on the touchscreen in front of him and the attitude control rockets in the ship’s nose fired, lifting it up. When the shuttle was vertical with respect to the ground below, he then fired the manoeuvring rockets on either side of the tail and the ship rose, trailing the tether behind it.

“This is when we find out of it’s still attached,” said Paul. “That last earthquake might have knocked it loose.”

“Better bloody not have,” said Eddie. “After everything we've been through. When will we know?”

“Just about...” said Benny, “...now. We should feel a jerk as we reach the end of the tether.”

They all tensed up but no jerk came. They waited in growing tension as the seconds passed. Paul looked anxiously across at Benny, but he had his eyes fixed on the instruments in front of him. Eddie looked across at Susan and saw her staring up at the ceiling, a look of serenity on her face. She thought God had snapped the cable and was glad about it. Then she looked across at him. “You cannot go against the will of God,” she said. “It's folly to even try.”

“I have news,” said Benny, sounding grim. “The instruments just registered a small drop in our acceleration. Very small, too small for us to feel. It’s consistent to our towing a mass behind us of around one point four kilograms.”

Eddie's stomach sank. He felt black despair washing over him. “We only got a small piece of rock,” he said. “Relatively small, maybe still miles across, but way too small to pull the rest of the moon behind it with its gravity. The ground must have been shattered, maybe when the Scatter Cloud first hit. We were always doomed to failure.”

“Any way of telling how big a chunk of rock we've got?” asked Paul.

“There’s a rear facing camera,” said Benny. He pointed at a cluster of small screens near the top of the instrument panel. He touched a control and the image from one of them was transferred to the main screen. It showed the surface of the moon, now free of dust and wind. Just bare rock, almost completely smooth, filling the screen. Benny turned the camera to look sideways until a horizon came into view, but the edge was still hidden by the curvature it had had as a piece of the moon's crust. It could have been ten miles across or a thousand.

“We continue with the mission,” said Benny. “Just as though everything were going normally. For all we know, maybe Lunar Rescue One has reduced the mass of the moon way more than we ever dared hope. Maybe we've got the entire two thousand kilometre wide section of crust and it weighs just one point four kilograms.”

“Yeah,” said Eddie. “Maybe.”

“So. Prepare to turn your device off, Eddie. I'll turn off Lunar Rescue One when you've done it, but be prepared to turn it back on again before we hit the ground.”

“Roger.”

“Okay. Flip the switch in three, two, one, now.” Eddie did so, and Benny touched a control in front of him a moment later. The mass dampener attached to the front of the Long March rocket was turned off and the moon's full mass was restored. All the air, rocks and droplets of magma that had been thrown up into space felt their outward motions slowing under the influence of the moon's collective gravity. It all dropped and began to fall again, as did the Shuttle and the mass of rock to which it was attached. Its engines continued to fire, but they had far too little thrust to resist the full mass of the moon.

The huge section of lunar crust tethered to the Shuttle fell back towards the moon, but the crust had mass and gravity of its own and exerted its own attraction on the main bulk of the moon, which now consisted entirely of molten rock. The entirety of the moon, solid and liquid together, was therefore moving very slightly faster in its orbit around the Earth, moving into a very slightly higher orbit. If they did nothing more, therefore, the moon's next close approach to the Earth wouldn't be quite as close as the last one had been.

“Are you watching our altitude, Ben?” asked Paul anxiously.

“I am,” replied the Swede, a little testily. “Switching Lunar Rescue One back on in ten seconds. Stand by Eddie.” The scene on the monitor showed the rock they were towing growing visibly as its gravity pulled them down, but they were approaching it more slowly then they otherwise would have because it was itself falling towards the massive ball of molten rock close behind it. “Ready, Eddie?”

“Ready,” Eddie replied.

“Okay. Flipping the switch now.” He turned the mass dampener on again and the moon once again flared outwards as its gravity vanished along with its mass and there was nothing to resist its internal pressure. Eddie flipped the switch on the mass amplifier and the shuttle's engines began to brake its fall towards the mass of solid rock beneath it. The crew tensed up as they saw it continuing to approach, but they gradually slowed, came to a halt and began to rise again. A few seconds later they once again reached the end of the tether and began pulling the rock again. “We're now pulling a weight of one point two kilograms,” said Benny. “We lost some of it.”

“Hopefully, we've still got enough,” said Paul. “I just wish we knew how much rock we’re towing. Are we actually accomplishing anything or are we risking our lives for nothing?”

“Guess we won’t know until we’re back in radio contact with Earth,” said Eddie. “Until then, we can only keep doing what we’re doing and hope for the best.” The other two men nodded their agreement while, unnoticed by any of them, Susan continued to work on the zip ties holding her to the chair.

☆☆☆

“As you can clearly see,” said the television commentator, “The entire remaining solid crust of the moon has pulled completely away from the molten remainder. A curving slab nearly a thousand kilometres across and estimated to be two hundred kilometres thick in the centre... Oh, look at that!” As the Wetherby scientists watched in breathless awe, a ‘thin’ section of crust near the edge broke off and fell with majestic slowness towards the spreading globe of molten rock beside it. When it hit, it caused the biggest splash the solar system had known in three billion years. Molten rock heated to incandescent temperatures rose almost too slowly to see, first on one side of the dropping fragment of crust, then on the other as it hit edge on and sank, slowly but inevitably, out of sight. Beside it, other fragments of stone breaking away from the main mass, each one the size of the dinosaur killer asteroid, went almost unnoticed.

Ben Wrexham felt his heart hammering with excitement as his brain struggled to comprehend the scale of what he was seeing on the big, wall mounted television screen. Around him, he heard the others gasping with shock and saw hands clenched white as they gripped those of the people sitting beside them. Unlike the majority of the world's population, for whom it was little more than a firework display in the sky, these people knew the magnitude of what they were seeing and thought that four hundred thousand kilometres was far too little distance between it and the home of all humanity.

“If just one of those fragments comes our way,” said Frank, “it’s the end of everything. There's nothing we could do to stop it. Nothing we could do but sit here and watch it come.”

“There's no way any of it could come our way,” said James, though. “It's all gravitationally bound together.”

“Not when the mass dampener's turned on, and there's so much we don't know about what goes on at the very centre of large worlds. Who knows what sudden release of energy there might be, larger than the moon's gravitational binding energy?”

“If something like that were going to happen, it would have happened by now.”

“Would it? Things on that scale take time. It's got to burrow its way up through a thousand kilometres of molten rock.”

James turned to Samantha. “You're the expert. Is it possible there could be something exotic going on in the heart of the moon?”

“We’ve never seen any evidence for anything other than a solid, nickel, iron core. We've never observed any phenomenon that required an unconventional explanation.”

“Which proves nothing,” replied Frank. “Nothing like this has ever happened to the moon before.”

“Well, it’s too late to worry about it now,” interrupted Ben before James could reply. “At the moment, everything's going to plan. They've hooked a chunk of the moon that’s more than big enough to do the job. So long as nothing unexpected happens, they're on their way to triumphant success.”

The others took the hint and they watched silently as the commentator continued to give a running commentary on the titanic events taking place on the screen in front of them.