Of all the stupid things Maddy had done in her life, and there were more than she cared to admit, this rated up there with the best of them.

Once, back on the Slowboat Endeavour when she was fourteen and had just completed her university degree, she rushed to show her father the message she'd received confirming her qualification as a communications technician. It meant she'd be able to work for a living and help her father bring in the credit that meant more luxuries in their sparse colonist lifestyle. Proud of herself and eager to tell her father the news, Maddy had decided to take a short cut through a temporarily closed passage between decks, slipped in her haste as she rounded a corner and skidded across solid steel flooring to slam into a bulkhead. She broke her arm and took a remarkable quantity of skin off her backside. Her father also had the humiliation of paying the fine imposed for entering an off-limits area of the ship.

That had been stupid.

But it was sensible compared to what she was doing now, walking as the last in a line of three figures across the unforgiving hard iron surface of Shiva.

Progress was slow, made so by the razor-sharp edges of the craters where other bodies had slammed into the surface of the asteroid, melting the iron which splashed and then resolidified to form outlandish shapes and spears. One indiscreet touch and a space suit might be punctured. The terrain was lit only by the lights on their helmets, which cast narrow beams. They moved in long, loping strides in the preciously weak gravity, judging each step carefully. The bounding rhythm of look, stride, soar, land and recover quickly became exhausting.

The horizon was close, barely more than a hundred and thirty metres away, which meant a constantly changing line of sight that misdirected her eyes, especially with the necessity of watching where she placed her feet. Each time she looked up the landscape had completely changed. All bearings were quickly lost.

Reed was a few metres ahead, bouncing along on his sturdy Helot feet, with Marshall a tall grim shadow behind him. Every minute or so he would turn and look over his shoulder at Maddy, who nodded each time as if to reinforce the fact she hadn't fallen behind or tried to escape. Where he thought she might go on this blasted piece of scrap metal was anyone's guess.

She sucked some water from her suit's reservoir through a drinking tube and listened to the laboured breathing of her companions over the comlink. It had been forbidden by Reed to use any unnecessary communication, even on a private sub-channel which would not go beyond the three of them, otherwise she would have called up the ship and informed Geranium of their progress. Thoughts of the girl worried the back of her mind even as she focused on not falling over.

Reed held up a hand to warn them to stop. It took a second or two for Maddy to readjust her last jump so as not to slam into Marshall ahead.

They were at the top of a small rise, so their horizon had shifted back. On the flat plain below, three space-suited figures—Helots by their build—stood beside a small space dinghy, working on some structure that had been erected on the surface. Nearby searchlights illuminated the scene.

Reed knelt down and turned off the light on his helmet. The others did the same and darkness engulfed them. The Helots worked without apparent supervision, which was unusual enough even here for Maddy to double check there were no Sapes around.

'What are they doing?' Reed whispered instinctively despite their private channel.

'They don't look like terrorists to me,' muttered Marshall. 'More like engineers.'

'They are engineers you idiot. Maddy, what do you think?'

It was some kind of thrust engine, she was fairly sure, which made sense when she remembered the whole asteroid was meant to be moved out of its orbit. But they were unlike any engines she'd ever seen before. It would be interesting to see the electronics behind them; if those people weren't working on the thing, she'd be tempted to have a closer look.

'I don't know.'

There was a growl from Marshall. 'There's only three of them. I have weapons. Looks like they're unarmed.'

The distance was close enough for a few well-placed shots. For a moment it looked as if Reed was going to order the other to open fire, but he pulled himself further down behind the rise.

'I'd like to speak to whoever's behind this.'

'What?' Marshall clenched his fist over the butt of his plasma pistol. 'They're terrorists according to Maddy. You're going to talk to them?'

'I'm a terrorist too. I know how they think.'

Marshall turned his back on the scene and sat down.

Looking over the rise, Maddy continued to watch the workers. Marshall had a point: they could take these three out easily enough. There were certainly no visible weapons anywhere, not even on the dinghy. Talking to the terrorists and asking them to please stop carrying out their plans was insane. Besides, it didn't look like they were doing anything at all menacing. Perhaps the whole thing was a mistake. Perhaps she'd misread the ghost data: this was just a normal asteroid work team doing normal business.

'Look out!'

Marshall drew one of his guns and pointed it upwards. Dust stirred up around Maddy as she turned to follow his gaze.

A dinghy hovered about twenty metres above them, the downpush of its lifters a palpable force on her body. A light shone down illuminating the small group below the rise. Marshall drew one of his guns but Reed put out a hand to stop him. The door of the dinghy opened and space-suited form leaned out. It held some kind of tool that looked like it might do some damage to a space suit.

'Drop your weapons!'

Marshall's finger twitched on his gun, but he glanced at Reed instead of firing and lowered his hand.

The dinghy settled on the ground a short distance away. Maddy turned to glance back at the group around the engine and saw them walking towards her.

Out of the dinghy stepped yet another person, a Helot by the size of him, holding some sort of harpoon gun.

'Drop your weapons!'

Marshall hesitated a moment, but seemed to assess his options. In the end he dropped the gun in his hand, removed the other from its holster and let it also fall.

The Helot with the harpoon moved forwards. The others had now reached the top of the rise and encircled them. Four Helots, and possibly another one in the dinghy.

'I'm Reed Hasur. A Helot of Earth. I wish to speak to your leader.'

'Don't move!'

'I'm not moving as you can see. Your leader may know me. I wish to speak to him.'

There was a burst of gabbled language over Maddy's comlink: the Helot tongue. She'd heard it before, but didn't understand it. Nothing to do but stand and wait.

After a moment Reed's voice switched back to Inglish. 'This is Maddy Hawthorn. You may know of her, too.'

Why had he said that? These might be Shamah terrorists, the old group she'd been forced to work with a year ago. They wouldn't take kindly to her. For a moment Maddy thought of Geranium back on the ship: the girl might well be a prisoner now, too. Or dead. Maddy felt her heartbeat quicken a half second before her suit's medical monitor informed her in a mild tone that her pulse had become dangerously high. She took a deep breath in an effort to calm herself, but the sound went out across the comlink. All turned to look at her.

'You have something to say?' The Helot aimed his gun at her.

'I...no.'

'I have heard of you. What are you doing here?'

She closed her eyes for a moment—behind the visor of the space helmet perhaps the gesture wouldn't be seen. What to do? Say nothing at all? But there was really no choice.

'We believe you are trying to move the asteroid,' she said, opening her eyes again. 'We came to find out why.'

More talk in Helot. Reed seemed to raise his voice a few times.

'You will come with us,' said the Helot eventually.

Two other dinghies appeared over the horizon from different directions and landed nearby. Helots emerged from each and stepped over to the small group.

'One of you in each dinghy.'

A Helot started walking back the way they had approached, down the rise towards Reed's ship. Doubtless he was being sent to check on whether any more of them were on board. He would find Geranium—Maddy hoped the girl had the sense to come quietly.

Nothing was said as they climbed into the dinghies. Maddy was pushed into a small seat at the back, with a female Helot facing her and one giving instructions to the dinghy's AI. The craft rose with hardly any effort and flew in a gentle trajectory towards a larger ship that now appeared rising above the asteroid in a high orbit. It was Maddy's first glimpse of the Shepherd Moon.

It occurred to her it might also be her last.