For the tenth time, Geranium opened the comlink channel and waited for a return beacon. Nothing. Despite knowing it was utterly useless, she spoke into it anyway. 'Maddy? Are you there? Maddy? It's Geranium.'

Not even static came back.

The cabin lights were turned down, and through the window was nothing but the blasted surface of Shiva, hardly less black than space itself, visible only because of faint sunlight gleaming off the iron ground. It was utterly bleak and the most depressing thing Geranium had ever seen.

Not that she'd seen much. Of course, she hadn't realised it before now. Dealing with her parents had taken up so much time she could have been doing other things, but it had been her parents who gave her the ability to go to Mars. She missed them and her brother, and her little sister. She wanted to have Fantasy there right now, telling her one of her dumb jokes.

'And I decided to go to Mars,' she said aloud. That was where things had started to go wrong. It was all her fault really.

The cabin was not large enough to pace back and forth, but she couldn't sit still. Every minute or so she'd rise from her chair, bound around the cabin, sit at the table, climb into her bunk, emerge again and start all over. At one stage she even picked up her helmet and went to put it on, was about to walk out of the airlock and follow the others across the asteroid, but slammed the helmet down onto the table, swearing loudly.

How dare they leave her herePerhaps the woman was still just a terrorist, gone to join the others in smashing the Moon or whatever it was they were planning. She'd saved Geranium's life, but why? To bring her here, to have Sarti killed? It all made no sense. She picked up the helmet and was about to slam it down again just for the sake of it, when she paused and looked out of the window.

Someone was walking towards the ship.

Instinct made Geranium duck down behind the control desk to avoid being seen. She peeked above the desk. The person's suit was red, not grey, clearly visible against the dark iron terrain outside. Judging by the height, it was a Helot. One of the terrorists they'd come here to see?

She kept low on the floor of the ship, just her eyes above the desk, ducking down whenever she felt the person was looking her way.

What to do? She had no weapons, nothing at all. Nor could she ask the AI for an opinion, since it had been locked by Reed. It was just her, and there was nowhere to hide.

The helmet was still on the table. She grabbed it and pulled it down onto her head, felt the suffocating closeness of it for a moment before the suit's AI came online and started the air circulation. It was hard to stop herself taking huge gulps of it. Being inside the suit was like being in the middle of a huge crowd of people, with pressure from all sides and nowhere to move.

The person outside approached cautiously, probably checking for signs of life in the ship. Crawling across the floor, Geranium reached the airlock and stared at the controls beside it: inner and outer door controls, air pump switches and an emergency override contact that would close the inner door instantly in the event of an air breach. She reached up to the contact and opened the inner door.

Inside, she could stand up since she wasn't visible to the approaching Helot. It took a minute for the air to be removed from the chamber. When the green light illuminated Geranium slowly opened the outer door. The access ladder was in place down the side of the ship, but she chose the faster method of a simple jump down to the surface; in this gravity her feet barely stirred the iron dust at the foot of the ladder. She pressed the contact to close the outer door of the airlock then looked around for somewhere to hide. It was the first time she'd ever set foot on a totally airless world, but there was no time to waste in adjusting to new experiences.

Geranium Petunia, you are an idiot!

Of course, what she should have done was lock the door from the inside. The intruder wouldn't be able to get in and might assume the ship was empty of crew.

You really are a dumb bitch.

No time now to kick herself. And no time to put the alternative plan into action.

Behind the ship, about ten metres away from the airlock door, was a crater wall piled high on one side with a twisted outcrop of iron, as if the meteoroid that had slammed into Shiva billions of years ago had struck a glancing blow, melted and pushed the iron up ahead of it, which had then cooled again into a permanently frozen wave. It soared higher than her head, the crest adorned with razor sharp daggers of metal.

Her first step ended with both feet leaving the ground. She had the presence of mind to land on both feet at once, which produced another kangaroo-like bound that took her behind the crater splash. It was just in time, as the space-suited figure appeared, bounding around from the bow of the ship.

She stood for a minute with her back to the wall, both hands pressed against the surface, fancying that her breathing, which sounded so loud in her own ears, could be heard by the other person. It was such a strong conviction that she actually held her breath for a moment, then came to her senses and exhaled.

'Normal breathing is recommended,' said the suit's AI.

'Shut up.'

She uttered the words before she realised it should be possible to take the AI's vocal communications off line, only she didn't have the time to search through the sub-routines to discover how to do it.

Outside her tiny enclosed world was absolute silence, and almost total darkness. She pulled herself away from the wall, turned and looked out from the side of the frozen metal wave.

The Helot was at the door of the ship, his back to Geranium, shining a flashlight over the hull. He had courage, that was for sure, because there was no way he could know if the ship was occupied or armed. As Geranium watched he pressed the contact to open the airlock, climbed the ladder and stepped inside.

She activated her suit's comlink, then stopped before she said anything. This Helot could be listening into any communications. No doubt he'd told his companions about finding the ship. Reinforcements might already be on the way. If she tried to contact Maddy or the others, he would know there was someone nearby.

The airlock door closed. After a minute she could see the cabin lights come on. There was a long pause. Was he searching? It wouldn't take long to ascertain there was no one on board. Was he trying to move the ship? He wouldn't succeed, unless he was able to bypass Reed's password.

A horrible thought occurred to her: perhaps this man had been sent by Reed to fetch the ship. Perhaps she was supposed to be on it, perhaps he was someone who had nothing to do with the terrorists and was in fact there to help. In that case, she should tell him she was here, or get left behind.

She gasped as the conflicting desires to alert the man to her presence and to keep hiding tore at her. Both alternatives seemed doomed.

I can't do this. I need Sarti. Sarti would...

The airlock door opened again and the man stepped out: definitely a Helot, but shorter and bulkier than those she had experienced. Perhaps he was one of those new ones Maddy had mentioned, a Serf or whatever they were called. In its dumpy space suit he looked meaner and stronger than any Helot.

He looked across at her hiding place and their eyes met.

'Fuck!'

Ducking behind the wave, Geranium shouted the word inside her helmet, the sound reverberating in her ears.

'Increased volume is not necessary in order to communicate,' intoned the suit's AI.

'Shut up shut up shut up!'

All she could do was run. But that proved impossible in the negligible gravity. She shoved herself away from the wave with a huge thrust of her arms, sailing through the air to land twenty metres away. She kangaroo-hopped again, pushing down with both legs as hard as she could, flying high above the terrain before arcing down once more.

Her second landing took her close to the centre of the crater. She was now in a hollow, and looking over her shoulder she saw the Helot take his second bound towards her. He leaped high, visor reflecting Geranium's cowering form as he descended, to land within two metres of her.

She crawled backwards, scrabbling at the surface as he advanced.

'No,' she said, although there was no way of telling if he could hear her. 'I give up. You don't have to—'

He reached down and hauled her upright with one hand, pushed his face close to hers. She could see him clearly now, a hard-faced Serf, eyes glaring.

'Who are you?' His voice was thick and low.

'Please. Don't hurt me.'

'Who are you?'

She opened her mouth to reply, then clammed up. It would be dangerous to tell him, more dangerous perhaps than keeping silent. Until she knew more about what had happened to the others, she would give away no information. However much it hurt.

With a grunt of rage rather than effort, he hurled her to the ground. The impact jarred her through her suit, but the AI never lost its calm tones as it advised her that further shocks of that nature would risk compromising the suit's integrity.

She lay there, staring up at the Serf, who raised a foot and appeared about to kick her. She rolled away, the effort taking her further than she intended. Scrambling up onto hands and knees, she watched the Serf jump towards her.

It was time to run again. He had more strength than her, but was hampered by a stocky frame and short legs; his kind was not designed to run. Geranium had youth and a slightness of mass which even in that negligible gravity added metres to her leaps and bounds. Racing back to the iron wave, she bounded past it over to the ship and hit the contact to open the airlock door.

He reached her before she could climb inside. The inertia of his movement carried him past his landing point to slam into the side of the ship. Geranium grabbed the ladder and hauled herself up and inside. Just as the door began to close he fastened a gloved hand on her ankle and tried to pull her back. There was nothing for her to hold onto, but she managed to plant her other foot on the door frame as he hauled on her leg, pulling himself inside the airlock as the door closed.

As soon as the outer door sealed the chamber began to fill with air. Geranium lay against the inner door and fell inside the ship when it opened. Before she could rise the Serf had grabbed her again and entered the ship as the inner door closed. A green light came on and the ship's AI confirmed the environment was secure.

She fell back against the table, staring at the Serf who advanced again. He grabbed her arm, pulled her across the cabin to a bunk bed and opened it. He tried to shove her in, but her helmet was too bulky to fit past the frame of the cubicle.

'Take off your helmet!' he roared, and she reached up to unclasp the connections. As air hissed around the seals he pulled the helmet off, the edges of which stung her ears. He threw the helmet across the cabin and shoved her into the cubicle. Then he shut the door and locked it.