Paul was jerked out of his sleep by the howling of the alarm. "Emergency!" cried the recorded voice from every speaker. "Emergency evacuation! Emergency! Emergency evacuation!"

"What's going on?" he demanded as he struggled free from the elastic webbing. He threw open the curtain of his cot and climbed out to float in the middle of the module. He swam through the air, dressed only in his nightclothes, to the command module where Lauren was having an urgent, almost panicked conversation with ground control. "What's going on?" he demanded again.

Lauren looked around at him, her eyes wide with fear, then returned her attention to the monitor screen. "How long have we got?" she asked.

"The first particles could be arriving at any moment," the face on the screen replied. It wasn't someone Paul recognised. An elderly man with a neatly trimmed grey beard and wire frame spectacles. "We don't know if you're in any danger, this is purely precautionary, but we want you all on the ground within three hours. Put the station in ASCR mode and leave in the Colibri and the emergency re-entry modules. Immediately!"

"Roger!" said Lauren above the sound of the alarm. She reached out a hand and turned it off. Silence fell except for the distant voices of the other crew members asking each other what was going on. Lauren's fingers were already tapping on the touchscreen in front of her, bringing up the option to put the space station into Assured Safe Crew Return mode, in which it would operate automatically until another crew could be put back aboard, when the emergency was over. "ASCR mode activated. Prepping the re-entry craft for departure."

"Lauren!" cried Paul, growing increasingly alarmed. "What's going on?"

"There's another Scatter Cloud," the station commander replied, struggling to remain calm as she unbuckled herself from the seat. "A much bigger one. Heading right for us. The station could be holed. We've been ordered to evacuate."

"Shit!" Paul looked down at himself, still dressed only in his thin, cotton underclothes. Station protocol specified that, in an emergency evacuation, clothing was unimportant and that everyone should get to their assigned evacuation vehicle dressed in whatever they happened to be wearing at the time, but he still toyed with the idea of pulling on his shoes and jumpsuit. It would only take a moment...

Lauren saw the thought in his eyes, though. "Get to the Colibri!" she snapped. "Now!" Paul nodded and grabbed hold of a support strut to turn himself. Then he kicked himself away, back through node five and towards the Rotterdam module, to which the European shuttle was docked.

There was a 'Zing!' sound, simultaneously to his left and to his right. He froze in alarm, but nothing else seemed to happen. "What was that?" demanded Benny from the entrance to node two.

"Nothing," said Paul. "We'll look into it later. Let's just get off this station first..."

"Air pressure warning!" said the station's computerised voice. "Air pressure drop in the Rotterdam module! Close all airtight doors immediately and follow puncture repair procedures."

"Ignore it!" said Benny. "It'll take days for the pressure to drop dangerously low. Leave it for the next crew."

Paul nodded and began to move towards the airlock, but the computer voice spoke again. "Air pressure in the Rotterdam module has dropped to nine hundred millibars. Close all airtight doors immediately and follow puncture repair procedures. Air pressure in the Rotterdam Module is now eight hundred and eighty milibars. Close all airtight doors immediately and follow puncture repair procedures."

"Shit! It's falling fast!" said Jayesh, who had also just arrived. He closed the hatch he'd just come in through. "Must be a big hole! And the others aren't here yet!"

Paul nodded. It wasn't certain that the others would be coming this way. The two emergency re-entry modules were located as far away from the Colibri and each other as possible, in case some disaster caused people to become cut off, unable to move freely around the space station. It might be that none of the others would be coming this way, but if they were, the only way to get to the Colibri shuttle was through the Rotterdam module.

"Where's the repair kit?" he demanded, looking around the crowded module. There were equipment and storage lockers all over the place, a jumble of colours and geometric shapes that made it hard to find one specific thing in the midst of it all. Punctures causing air leaks were usually small. Harmony had suffered several in the years since it had become operational, each one just a couple of millimetres across, and they'd had hours, even days, to find them before they became a problem. It hadn't been thought necessary to made the repair kits easy to find, therefore. Not like the fire extinguishers that glared an angry red next to the airtight doors. Paul scanned his eyes across the room in increasing frustration, therefore. "Where the hell is it?"

"Air pressure in the Rotterdam module has dropped to eight hundred milibars!" announced the computer voice. "Close all airtight doors..."

"Yes, I know!" snapped Paul angrily, his ears popping painfully. "Where the bloody hell..."

"Here it is!" cried Jayesh, pulling it out from behind the tool locker. He pulled it open and pulled out the tube of foam sealant. "Now, where's the leak?"

Benny, meanwhile, had torn a page from the airlock service manual and had been tearing it into small pieces. He scattered them into the air, and the other two men watched as they tumbled over and over, spinning like snowflakes. "Keep still!" warned the Swede. "Don't disturb the air!"

All three men froze, watching the tiny flakes of paper as they drifted across the module. Some of them were drifting towards the portable air tanks, and Paul allowed himself to drift closer. He could hear it now. A loud hissing, like an air hose as it was refilling the tanks of a spacesuit after an EVA, but louder. Alarmingly, terrifyingly loud. He could feel it now. A coolness against his bare arms and legs as the air moved past him, its temperature dropping along with its pressure. "Gimme the sealant!" he cried. Jayesh pushed it through the air towards him.

Paul snatched it out of the air, then stared at the bulkhead, searching for the hole. His eyes fixed on a tiny scrap of torn paper and followed it as it drifted towards the curving steel surface. There it was! A gasp escaped him as he saw the size of it. Fully two centimetres across! Big enough that he could have poked his finger out into the vacuum of space on the other side!

Could the foam seal such a large hole, or would it just be sucked through before it could set? Only one way to find out. He popped the lid off, pointed the can at the hole and depressed the top. Foam sprayed out, and most of it did indeed get sucked right through, but some hit the sides of the hole and stayed there, building up into a kind of volcanic cone with a hole in the middle. He kept on spraying, growing the volcano larger and larger until the hole finally filled in and the flow of air ceased. He took his finger off the top and the spray stopped.

"The other one's here!" cried Benny. Paul spun around. He'd forgotten that there must be two holes. An entrance and an exit wound. He grabbed hold of a spacesuit attached to the bulkhead beside him and used it to turn himself around. Then he pushed himself across the module to where the Swede was waiting, pointing to where a cluster of small scraps of paper had gathered around the second hole.

Was there enough foam left in the can to fill another hole the same size? He doubted it, but then a thought came to him. "Tear another page out of that manual!" he cried. Benny did so and handed the sheet of paper across. Paul took it from him and placed it across the hole. The paper creased up as the suction began to pull it through, but Paul sprayed foam across it before it disappeared from sight. The paper stopped the foam long enough for it to set and a moment later the hole was sealed, one corner of the paper still visible under the scab of foam covering the wall.

The three men breathed sighs of relief. "Good!" said Paul, releasing the can to float freely in the air. "Okay, let's get aboard the shuttle."

Jayesh swam through the hatch, but as Benny went to follow him the hatch to node two opened and Susan poked her head through, her long hair waving around like seaweed in a slow current. "Are we evacuating?" she said. "What's going on?"

"Get in the shuttle!" said Paul. There'd be time for explanations later. "Where are the others?"

At that moment, the intercom came to life. "This is Bao and Zhang from Evac Module One. Is anyone else wanting to use Evac Module One?"

"This is Paul in the Rotterdam Module," Paul replied. "Benny, Jayesh, Susan and myself are leaving in the Colibri."

"This is Lauren and Ying," the speaker then said. "We're in Evac Module Two. If everyone's in an escape vehicle then go! Immediately!"

"Roger!" said Bao. "Launching immediately! Good luck everyone!" A moment later the space station gave a slight lurch as the clamps unlocked and the three spring loaded arms pushed the module gently away.

Susan followed Benny into the shuttle and Paul followed after her. At least Maggie will be pleased by this, he thought as he closed the hatch behind him. It wasn't the way he'd been intending to come home, but he was coming home none the less. She'd pretend to share his disappointment at having his mission cut short, but inside she'd be delighted and, if the truth were told, he'd be glad to be home as well. He smiled as he imagined the reunion party they'd throw to celebrate his safe return. They'd invite everyone...

"Air pressure warning!" said the computer voice. "Air pressure drop on the Heineman Module! Close all airtight doors..."

"Who cares?" said Benny with a smile as he swam through into the shuttle cockpit. "The next crew can take care of it."

"Two hits!" said Jayesh. "We must be passing through a dense part of the cloud! The shuttle could be hit!"

"If it's God's will," said Susan.

"The shuttle's a small target," said Paul. "The Evac Modules are even smaller. The station's huge. We'll be okay."

"Right!" said Benny, going quickly through the emergency separation checklist. "Three hours from now we'll be breathing clean, fresh air again! Not this recycled muck! The first thing I'm going to do when we get back on the ground is go to the nearest restaurant and order their biggest pickled herring!"

"This is Lauren Kelly," said the commander's voice over the intercom. "We're about to launch. Last chance if anyone wants to come with us."

"This is Benny Svanberg. Paul, Susan, Jayesh and myself are aboard the Calibri, about to launch."

"This is Bao and Zhang. We are safely separated in Evac Module One, about to fire de-orbit thrusters."

"Roger that," said Lauren. "We're separating now, in that case. Good luck everyone!" A moment later the station gave another lurch as the second emergency escape module separated and began its journey back to Earth.

"Just us, then," said Benny, his fingers tapping the shuttle's touch screen. "Everything looks good. Everyone buckled in?"

"My God!" cried Susan, staring out through the tiny, round window beside her seat. "Look at that!"

Paul twisted around in his seat so he could look. The night side of the Earth was hanging there beside them, glittering with cities. Paul had seen it a hundred times before and the sight always enraptured him, but this time it was different. Streaks of light were passing across it, each one a tiny meteor burning up in the atmosphere, except that they weren't burning up, they couldn't be, not if they were as impossibly dense as the components of the first cloud. They would be reaching the ground and passing straight through earth and rock, scarcely slowing, only giving up their momentum one tiny bit at a time. Would they explode, deep below the ground? Paul wondered. Perhaps with enough force to shake the ground above and bring buildings crashing down in ruin? Or would they just keep slowing until they came to a gentle stop, perhaps continuing to sink at a snail’s pace until they finally settled at the centre of the Earth, centuries or millions of years from now? That probably depended on what they were made of, he mused, something that still had experts all over the world scratching their heads in puzzlement.

“If anyone’s left the gas on, this is your last chance to go back and turn it off,” said Benny, a wide grin on his face.

”If we’re going, let’s just go!” said Susan, her eyes wide with fear. “We could get hit any time!”

Paul reached across to take her hand. She jerked her hand back in surprise at the first touch of his fingers, spinning her head around to stare at him, but then reached back out and allowed her hand to be taken. Her fingers were cold as they closed tight around his. She smiled nervously and Paul gave her a reassuring smile back. “We're going to be okay,” he told her. “You'll see.”

“Casting off,” said Benny, touching the flashing panel on the touch screen. They heard a clunk as the locking clamps opened, and then they felt a gentle backwards motion as the spring loaded arms pushed them away from the space station. In front of them, through the cockpit windows, they saw the looming bulk of the Rotterdam module begin to slowly shrink, the guide lights around the docking port blinking steadily as if everything was normal. Paul found it strangely reassuring and allowed his attention to remain focused on them.

“Closing nose covers,” said Benny, and the triangular sections of hull closed, hiding the airlock’s outer door and creating a smooth cone of heat resistant tiles across the shuttle's nose.

“I shouldn't be scared,” said Susan, looking at Paul. “My faith should give me comfort and strength. Why should I be scared when I know I'll go straight to heaven if I die?”

“It's normal to be scared,” Paul replied. “We're in actual danger at the moment. If you weren't scared, then I'd be worried.”

“But I should have more faith! If it's God's plan that we all die today, then I should rejoice, not quiver with fear.”

“Fear serves an important function. It gives you extra strength, sharpens your reflexes. Helps you survive when danger threatens. God gave you the capacity for fear for a reason. You should give thanks for it.” She smiled gratefully at him and gave his hand an extra squeeze.

“Performing yaw manoeuvre,” said Benny, his fingers playing on the touch screen like a musical instrument. A moment later, Harmony's solar panels came into view through the cockpit windows as the shuttle turned to bring its thrusters facing in the right direction for the de-orbit burn. Even as he watched, Paul saw a cloud of glittering motes erupt from a support strut as another cloud particle hit it. The solar panels had no doubt taken several hits by now, enough to reduce their output by quite a considerable amount. The next crew to occupy the station would have to make do on minimal power until they could make repairs.

There was a zing, the exact same noise they’d heard in the Rotterdam Module, and Paul tensed up in sudden terror. “We've been hit!” he said. Susan's hand tightened around his with painful force and he looked around, trying to see a hole in the shuttle's skin. “Where? Where were we hit?”

“Where's the foam sealant?” demanded Jayesh. “Oh, I see it.” He unbuckled himself from his seat and floated upwards to where it was stored, in a glass fronted alcove near the ceiling. He pulled it open and yanked the bottle free. “Where?” he asked, staring around.

“Do the trick with the torn up paper,” said Benny. “There should be a set of safety instructions somewhere. Tear out the last page.”

Paul did so, tore it up and released the tiny pieces of paper into the air. It was the first time Susan had seen it, and she stared in fascination as they began to gather up near the ceiling. ‘There it is,” she cried. “God, it's huge!”

It was the same size as the one in the space station, nearly two centimetres across. The cloud seemed to be made of particles that were all of a uniform size. Paul laid a piece of paper over it and sprayed it with foam before it could be sucked through. “Let's hope it wasn't travelling straight downwards,” he said, “because if it was...”

“The heat shield!” said Benny, his face grim. “If the heat shield's compromised...”

“We can’t go home,” Paul finished for him. “Not until it's fixed, anyway.” The heat shield was made of heat resistant tiles, held in place with a special glue. It was quite common for them to be damaged by space debris, and so every shuttle carried a few spares that could be cut to shape and used anywhere on the shuttle's underside. That required a spacewalk, though, and even the simplest spacewalk required lengthy preparation before the astronaut could step out through the airlock. And even then, when the job was done, the glue required twelve hours to set before the shuttle could perform a re-entry.

“Maybe it passed through at an angle,” said Jayesh hopefully, staring at the remaining scraps of paper floating around the cabin, but it was already obvious that they were settling towards the floor, towards a spot close by Susan’s foot. “God!” she gasped. “It just missed me!”

“I’ll inform ground control,” said Benny, opening the communications link. “Canberra, this is Pluvier. You there, George?”

“Right here, Benny. What's your status?”

“We've taken a hit. We believe the heat shield’s been compromised. We need to assess the situation and make repairs before we can return to earth.”

“Roger that, Benny. Suggest you return to Harmony. The rest of you might as well be comfortable while Susan does her thing.”

Susan looked up sharply, a look of shocked realisation on her face. Of course! With Zhang and Lauren both on their way back to Earth in the re-entry modules, she was the only one left qualified to perform a spacewalk.

“Roger, Canberra. Returning to Harmony.” He reached out a hand to sever the connection, but Paul unbuckled himself from his seat and swam forward to the empty seat vacated by Jayesh, who was sealing the hole in the floor. “George? Lauren said it's another Scatter Cloud. Is that right?”

“That's correct, Paul. The astronomers spotted a bunch of asteroids that had been thrown around by it a few weeks ago. They crunched the numbers and were able to determine its mass and flight path. It's big, Paul. About ten to the eighteenth tons. That's over ten percent the mass of the moon.”

There was silence in the shuttle for a moment as they digested the news. “And it's coming this way? Heading towards the Earth?”

“Heading towards the Earth, Moon system, we can't really narrow it down any more than that until the eggheads finish their calculations. Another hour or two, they say. They think it consists of a central mass consisting of about half the cloud’s total mass in an area a few thousand klicks across, with the rest consisting of an outer halo that might be hundreds of thousands of kilometres wide. We think you’re passing through that outer halo now.”

“So does that mean the central mass is still on its way, or has it missed us?”

“We'll know more when we see how the orbits of satellites are affected. The good news is that, with Harmony fully refuelled, you should be able to making any course corrections necessary.”

“But everything else in orbit is going to be scattered to the four winds! Right after we just finished putting it all back where it belongs!”

“Not necessarily. The central mass could pass hundreds of thousands of klicks away. If it does, the satellites might scarcely be affected. Even if we lose everything in orbit, though, that'll be preferable to the worst case scenario.”

“That being the central mass hitting the Earth,” said Paul. He could feel his face turning white with fear. “How... How bad would it be?”

“Unsurvivable, but the Earth’s a small target, relatively speaking.”

“Yeah, so is the Shuttle. How are the others? Are they okay?”

“So far. Both escape pods have fired their de-orbit boosters, so they're committed. They're on their way back to Earth and nothing can stop them.”

“Lucky it was us that got hit, then, and not them,” said Paul.

“They're not out of the woods yet, but I really don't think they’re in much danger. The distance between cloud particles... You just got lucky.”

“Very lucky,” said Benny. “I was just moments away from performing our own de-orbit burn.”

“God was with us,” said Susan, who then began whispering a prayer of thanks under her breath.

Benny, meanwhile, had been manoeuvring the shuttle to align the docking port in its nose with the station's docking port again. “Never actually done this in real life,” he said, a nervous tone in his voice. “In simulation, yes. Hundreds of times, but not in real life. How come Zhang and Lauren aren't here? They’re the shuttle pilots!”

“Zhang just happened to be in the wrong part of the station when it all went down,” said Paul, “and Lauren probably thought that Ying should have a qualified pilot with him, just in case. Don’t worry, you'll be fine. The computer does most of it. The computer could do it all, really. There's no need to have a human at the controls at all. If you want, you could step down and let the autopilot handle it.”

“Don't trust computers,” said the Swede. “You never know if the programmer was having a bad day when he wrote that crucial line of code, put one little comma in the wrong place. No, you’re right. I can handle this.” He smiled reassuringly, then turned back to the controls. “Okay. One tiny little puff of thrust to take us in...”

Paul looked out through the cockpit window, where the tiny, blinking lights around the docking port were still flashing steadily on and off, telling him that all the station's automatic systems were working properly. Apart from a few small holes in the hull, it was still working perfectly. There was absolutely nothing to worry about. He took a deep breath, let it out slowly...

As they approached, the open flaps of the nose covers hid the docking port from sight, but Benny could still see it on one of his cockpit displays. A moment later there was a soft clunk and a slight bump that rocked them in their seats. “Good connection,” said Benny, grinning all over his face with relief. “We are soft docked. And now...” He touched the screen in front of him and another clunk came from the docking port. “We are hard docked. The shuttle is secure.”

“Okay,” said Paul, unstrapping himself from his seat and floating free. “Let's get back inside. Looks like Harmony's going to be our home for a little while longer...”