Unloading all the equipment in gravity, even low gravity, was, it turned out, a lot harder than loading it in freefall had been.

The reel of Skyhook cable was large, bulky and cumbersome and it took both Eddie and Susan to wrestle it through the narrow airlock doors. Eddie went first, stepping backwards, his clumsy, gloved hands trying desperately to grip the smooth aluminium casing as it slipped a centimetre or two with every movement he made. He had to keep putting it down to get a new grip on it before it escaped from him. "You okay back there?" he asked.

"Fine," came Susan's voice from his helmet speaker. She was having an easier time of it, going forward, while Eddie was uncomfortably aware that there was a three metre drop somewhere behind him. He had to keep testing that there was still a deck behind him before he put his weight on his backward searching foot. Also, there was a sill around the airlock door over which he might trip if he wasn't careful, and a fall of three metres onto hard, stony ground might do bad things to his spacesuit even in one sixth gravity. He couldn't see behind him. He could turn his head but not the helmet of his spacesuit which was fixed facing forwards, so he had no choice but to retreat blindly, one timorous step at a time, while Susan pressed the reel forward, impatient to get the job over with.

He moved his foot tentatively backwards, ready to take another step, and felt the sill against the back of his heel. "Stop!" he said to Susan. "We're there." He moved to the side, so that he could let the reel go past him. From this position there were holes in the round casing he could get his fingers into, allowing him to hold it more easily, and he moved closer to the outer door to look down. Three metres straight down. How were they going to get it down there? If this had been a properly prepared expedition, planned for years beforehand, there would be a mechanism to lower it gently to the lunar surface. Some kind of winch perhaps. Here and now, though, they had nothing but what they'd brought with them and their own ingenuity.

"I'm going to jump down," he said. "Then I'll stand at the bottom and take the weight of it as you push it out the door. Then I'll lower it gently to the ground. Okay?"

"Okay," replied Susan. Eddie waited for her to say something else, but she didn't. She'd been uncommunicative ever since landing, only speaking when necessary and then saying the very least she could. Eddie wondered whether she was in shock from the frights she'd had during the descent. He'd tried talking to her about it, but she would only reply that she was fine and then refuse to be drawn any further. Her work was fine. She knew what to do to get the job done and did it without hesitation or complaint, but Eddie feared that, when she was safely back on Earth and the pressure was off, she was going to have some kind of major breakdown. He'd heard that soldiers, back in the old days when they'd still fought wars, had often performed flawlessly in combat, no matter what the danger or the stress, and it was when they got home that it all caught up with them. So long as they were still under stress they were able to hold it all in, but once the stress was gone they exploded, like those fish from the very bottom of the ocean that expanded and burst when removed from the pressure of the depths. He hoped that wasn't going to happen to Susan. She'd seemed nice back on the space station, in the short time he'd known her there, and she was pretty too.

He turned his mind back to the matter at hand and looked down at the drop beneath him. It looked a long way, but Paul and Benny had made it okay. He wondered how they were getting on at the crater. They'd switched to another channel so that their conversation wouldn't distract Eddie and Susan, and vice versa, but as a consequence he was feeling uncomfortably cut off from them on this space ship (A real life, actual factual space ship!) that he had no idea how to operate.

Oh well, thinking about it wouldn't get the job done. He went right up to the edge, therefore, tensed himself up and jumped. He fell much more slowly than he'd expected, the low gravity took a lot of getting used to, and he landed easily with just one small stagger before he was able to steady himself. Then he turned and looked back up at the airlock door.

Susan was standing in the opening, looking down at him. Eddie returned to his previous spot, directly below the door, and raised his arms. "Okay," he said. "Push it gently forward. I'll catch it." She may have nodded, but if so he didn't see it. The interior of her helmet was too dark for him to see her face. She moved back into the airlock, though, and a moment later the round reel began to roll forward.

He heard her breathing harder over the intercom as she pushed it over the door sill, and Eddie moved directly below it. With his hands raised he could almost touch it. "Almost there," he said. "Just a little further..."

The reel began to drop. He caught it in his hands, but even in the low gravity it was too heavy and he couldn't hold it. It slipped out of his grasp and he dodged out of the way as it fell to the lunar surface. He tripped over a small rock and fell, but he twisted around as he fell so that he landed on his elbow instead of the life support machinery he was wearing on his back. He could only watch helplessly, therefore, as the rim of the reel landed on a boulder, which caused it to roll as it fell the rest of the way to the dusty surface. Its momentum then made it roll away across the surface of the moon like a runaway wheel from a car crash.

"Bugger!" he swore, trying to climb back to his feet. The spacesuits had been designed for floating around outside the space station, though, and the legs would hardly bend at all. He had to drag himself over to the shuttle and prop himself up against it. Susan jumped down beside him and helped him up with a hand to the elbow, and then he pushed himself away from the shuttle until he was once more upright on his feet. "Don't fall down," he warned her. He couldn't see if she smiled or not.

Once more on his feet, he looked around to see where the reel had ended up. It was grey, though, the same colour as the surrounding rocks and dust, and it was dark and gloomy. "Where the hell is it?" he asked. "Can you see it?"

"No." She was walking away from the shuttle in the direction the reel had gone. Eddie looked for tracks in the dust, but the stiff wind had blown them away almost immediately. He followed after Susan, scanning the ground with his eyes, looking for a smooth, round surface. "This is ridiculous!" he muttered to himself. "It couldn't have gone far, surely!"

The ground shook and they both froze in place. An earthquake! thought Eddie. No, a moonquake. A reminder that the ground they were standing on was little more than a thin raft sitting on a completely molten sphere of magma and steadily sinking. Did the moonquake mean that it was beginning to break up? If so, they might have less time than they thought.

The moonquake passed and Eddie resumed the search, but Susan continued to just stand there. Maybe she's seen something, he thought, and he looked in the direction she seemed to be facing. There was nothing there he could see, though. He looked back at Susan to see that she was still standing motionless. Concerned, he went over to stand beside her. "Susan?" he said. "You okay?"

There was no response, so he tried to see her face inside the helmet. It was too dark, though. He couldn't see a thing. It might have been an empty spacesuit that someone had left there as a joke. There was a light on his wrist, though. He turned it on and shone it in through her faceplate.

Her eyes were wide with terror. A fear so great that it had completely paralysed her mind and shut her down into an almost catatonic state. "Susan!" he said in sudden fear. "It's okay, it was just a little moonquake. It's over now. Susan!" He grabbed her arm and gave her a shake, but it had no effect. "Paul!" he said, switching to the communal channel. "Benny! Susan needs help!"

"What happened?" asked Paul, but at that moment there was a flash of blinding white as a bolt of lightning hit the ground somewhere nearby, accompanied by a clap of thunder like a bomb going off. It snapped Susan out of her paralysis and she shrieked, hunkering down and throwing her arms over her head. Another flash of lightning followed, and then another and another, each one accompanied by an explosion of sound that hit them with an almost physical force. Eddie expected to be hit, as the tallest thing in the immediate neighbourhood. He didn't know that the material from which the spacesuits were made was almost perfectly insulating.

"We shouldn't be here!" cried Susan. "God doesn't want us here! He's telling us he wants us gone!"

"It's just lightning," said Eddie, as soothingly as he could. "It's over now." He hoped it was true, and indeed no other lightning bolts followed, although they continued to flash on the distant horizon. "It's over now."

He tried to take her by the arm again but she pushed him angrily away. "God is angry with us!" she cried. "He has a plan and we're trying to thwart Him! We have to stop! We have to go back home, right now!" She turned and began loping back towards the shuttle.

Eddie followed after her, still calling out her name, but she ignored him. Reaching the shuttle, she jumped and caught hold of the airlock door on the first attempt, pulling herself in. Eddie jumped after her, but he misjudged the distance and sailed too high, giving him a brief view of the cockpit through the cracked window before he fell again. He tried to grab hold of the door on the way down, but Susan had already closed it and was turning towards the inner door, ready to enter the cabin. Eddie fell all the way back down to the lunar surface.

"What's going on?" demanded Paul. "Eddie? Susan?"

"The lightning freaked her out," said Eddie as he climbed awkwardly back to his feet again. "I think she just needs a little time to calm down."

Paul swore. "She told me she was scared of lightning," he said. "We should never have brought her."

"The Americans..."

"Bugger the Americans! What could they do? Come up and shoot us all? We should have brought Yu. This is my fault, I shouldn't have let her come."

Yu could never have helped to repair the Long March, though. She didn't have the electrical skills. Only Susan could have done that. Without her, they'd never have gotten as far as they had, and Paul knew it. He swore again. "We're on our way," he said.

There were recessed handhelds on the outside of the shuttle for astronauts to grab hold of during spacewalks and Eddie tried to grab hold of one as he jumped again. He succeeded and hung by one hand as he looked in through the small window. He saw Susan opening the inner door to enter the cabin. It closed automatically behind her. He pulled the latch to open the outer door again and manoeuvred himself around it to climb into the airlock. It wasn’t easy. The door had been designed to be entered either in space, when an astronaut could simply float in, or on a runway on Earth when there would be a flight of steps leading up to it. Nobody had ever imagined a situation like this one. He held onto the top of the door and reached down to the sill at the bottom of the opening. The he let himself drop. He caught the sill on the way down and then pulled himself up and into the airlock.

He saw Paul and Benny loping across the lunar landscape towards him, but he decided not to wait. He closed the outer door and began to cycle the airlock. “Susan,” he said meanwhile. “It's okay, Susan. Just relax. Take your helmet off and... No! Don’t take your helmet off!” He'd momentarily forgotten that the airlock had been designed to operate either with vacuum on the other side or breathable Earth air. It had never been designed to operate with poisonous air outside. It operated by simply allowing cabin air in until the pressure was the same on both sides of the door. Then, when the door was opened, the air on both sides was allowed to mingle. The result was that the cabin‘s air had now been contaminated with moon air. It would almost certainly be fatal to breathe, and there was no way to clean it out. They were trapped in their spacesuits until they arrived back at the space station.

He kept trying to speak to her in a calm, soothing voice. “I'm coming, Susan. The others are coming as well. You’ll be fine as soon as you've had a chance to calm down. We’ll laugh about this one day.”

“I have to do it, Eddie.”

“Do what, Susan? What do you have to do?”

“We have to leave the moon in its new orbit. This is God’s plan, you see? He has a plan for mankind and we can’t interfere with it.”

A cold chill ran down Eddie's spine as an awful possibility came to him. “What are you going to do, Susan? Don't do anything rash, don't do anything you’ll regret later.” He looked at the progress indicator showing how long it would still take for the pressure to equalise. How could it be taking this long? All it had to do was let air in! It should only take a few seconds! There were all kinds of safeguards built in, of course, to make sure the air wasn’t going through both doors and out into space. The ingress of air was deliberately slow, to allow the crew to take corrective measures if there was a problem. There was probably a way to speed the process up, in the case of an emergency when it was necessary to get someone inside quickly. Paul and Benny probably both knew what it was. He should have waited for them. He reached for the intercom controls to switch to the common frequency so he could ask them, but Susan was speaking again and what she said froze him with horror.

“I have to destroy your mass amplifier,” she said. “It's the only way to...”

“No! Susan, no! Please, no!” He pulled at the door controls but it refused to open. He searched for the override controls. There was a control panel on the wall beside the door. Physical buttons you pushed with your fingers and which were labelled with enigmatic symbols and acronyms. He reached out to press them at random, hoping to find the override by chance, but he might only make things worse. “Susan! We need the mass amplifier! We can't get home without it! If you damage it we'll be trapped here!”

He tried to remember if he’d locked the box the mass amplifier was in. He’d had no reason to (so he’d thought) here on the shuttle, with only trusted crewmembers with him. If he’d locked it, it would have been just from force of habit. Even if he had, the casing wasn’t that strong, it wouldn’t take her long to break through, and if he hadn’t then she had direct access to the delicate components, most of which were irreplaceable except back on Earth. He stared back at the progress indicator, which seemed to have hardly moved, and felt himself becoming panicky with desperation. He reached for the intercom controls again, but Susan was still using their private channel and he needed to talk to her, to make her see reason.

“Susan, it must have been God's will that we found the alien spaceship, don’t you see? Doesn't that prove that He wants us to put the moon back into its old orbit?”

“He's testing us,” Susan replied. “He wants to see if we have enough faith to submit to His will. He gives us the means to disobey him to see if we will turn away from it. Don’t you see? I knew all along that this mission was wrong. I was too weak, too scared to do anything to stop it. It took the lightning to wake me up. That was God shaking me back to my senses.” Another sound began to come over the intercom, the sound of a power drill biting into metal.

Eddie was almost in tears with desperation, but finally the progress indicator reached one hundred percent and the inner door opened. Eddie launched himself through it but forgot the low gravity and landed flat on his face in the cabin. He picked himself up and forced himself to move more carefully towards the ladder up to the cockpit. He could hear the sound of blows coming from above, Susan hammering on the casing with something, and he launched himself up through the hole in the ceiling in a single leap.

In the cockpit, he saw Susan holding a large power drill. The drill was sunk deep into the casing of the mass amplifier and she was turning it this way and that to allow the drill bit to cause damage inside. He saw two other holes in the casing where she’d done it before. The device might already be irreparably destroyed! He forced himself to move steadily towards her, not wanting to lose control of himself in the low gravity, and he took hold of the arm holding the drill. “Stop it, Susan! Please stop it!”

“You're too late, Eddie! Your device is full of holes! God be praised!” She refused to let go of the drill, though, and kept her finger on the trigger. She tipped it from side to side as it whined angrily, determined to cause even more damage to the device's delicate innards. Eddie took hold of the casing with one hand and the drill with the other and pulled it out, then pushed Susan away from the device. She stumbled backwards and landed awkwardly at the base of her seat.

Eddie moved to place himself between her and the mass amplifier, but she was still holding the drill and was pointing it at him as if it were a gun. “You cannot defy God's Will!” she cried. “He has made His will plain and I will carry it out!” Then, to Eddie's astonishment and disbelief, she picked herself up and threw herself at him, the drill outstretched as if it were a knife.

He grabbed her wrist as she came within reach, desperate to keep the whining drill bit away from his spacesuit. She twisted her hand, though, to bring the bit into contact with his sleeve. The outer layer of cloth was torn up and shredded into a tangle of woolly fibres. As he pushed her back, the overhead light shone in through her visor, illuminating her face, and he was shocked to see that it was twisted into a snarl of hatred. The surprise paralysed him for a moment, and she took the opportunity to push the drill towards him again. This time it sank deep into the fabric of his chest and, although it failed to reach his skin, it penetrated the water filled tubes of his cooling jumpsuit. A red warning light lit up on his visor display. Once again he grabbed her wrist and pushed her away from him, and then he pulled the drill from her grip with his other hand. She tried her best to keep hold of it, but was unable to keep a firm grip on it with her gloved hand. Eddie threw it across the room. “Susan! Get a grip! Snap out of it! This isn't you!” She struggled under him, though, trying to throw him off until Paul arrived and helped him to get her under control.

“What happened?” he demanded, but Eddie was too shocked and exhausted to answer and Susan, seeing that she wouldn't be allowed to cause any more damage, relaxed and lapsed into silence, panting with the exertion as she lay on the cabin floor. Seeing that Paul had her in a firm grip, Eddie then let go of her and turned to look at the mass amplifier. He cringed with horror at the sight of the holes in its casing, each surrounded by curling slivers of metal. He turned the box to reach the lock, and saw to his surprise that it was unlocked. Susan could have opened it and destroyed its most important and delicate components with the drill, but she had been too far gone in her madness to notice. When Eddie opened the casing, he was relieved to see that all the damage was to cabling and a printed circuit board, things that should be easy to repair with the parts and equipment they had on board. He breathed a sigh of relief.

“Doesn't look too bad,” he said therefore. “I think I can fix this.” Susan reacted with fury, struggling under Paul again, but he was easily able to hold her down. “Why did you do it?” he demanded, but Susan still didn't reply.

“It wasn’t her fault,” said Eddie, not looking up from his examination of the mass amplifier. “The lightning freaked her out...”

“What the hell is going on here?” said Benny, his head appearing in the stairwell. “Are you guys fighting?”

“Susan tried to destroy the mass amplifier,” said Paul. He was keeping a firm grip on Susan's wrists, but she clearly knew that it was over and had stopped resisting. “I may have failed,” she said, “but God knows that I tried. I won't have to face His wrath. That'll be all on you.” There was a tone of doubt in her voice now, though, as if she were gradually coming to realise what she had done. Her body began shaking as if she were crying inside her spacesuit, although no sound came over the intercom.

“Can I let you go?” asked Paul. “You won't try anything, will you?”

“I won't try anything,” replied Susan, a little sullenly, Eddie thought. Paul let go of her wrists and slowly climbed off her. She gathered herself up and sat with her back against the bulkhead.

“Damn,” said Benny, climbing fully into the cockpit. “This is the last thing we need! Now we’ll need someone to keep a constant watch over her! That means only two of us to do the work that needs doing, and we've only got a couple of hours to do it!”

“We could tie her to the seat,” suggested Eddie. “We’ve got plenty of zip ties.” He looked at Susan apologetically as he said this, but the darkness inside her helmet prevented him from seeing the expression on her face. At that moment, another warning light lit up on his visor display, telling him that the fluid level of his cooling system was getting low. He put the thought out of his head for the moment. The suit would be easy to patch and they had plenty of spare fluid. What was more worrying was the smell of stale eggs that was beginning to fill his spacesuit. It meant that moon air was leaking into his spacesuit through the hole Susan had made. His visor display told him that he was still breathing plenty of oxygen, but there might be toxic gases getting in. He left the mass amplifier, therefore, and went looking for a patch to put on his sleeve.