'Hold.' Pyerpoint went off line. Shom wondered how the old man was going to handle the matter. Shom had noticed something odd about Margo in the last few months, but never thought she would disappear like this.

Pyerpoint came back on line, his voice more confident.

'Shom,' he ordered. 'I intend to take full responsibility for the chief of security. You are to take on her duties for the present.

I want no mention of the matter in any official report and there is to be no discussion of it within ranks, or outside. You understand this?'

'Yes, sir.'

'Furthermore, you are not to attempt to locate or contact the chief. I have known her for many years and I feel it will be better for me to deal with this, privately.'

'Yes, sir.'

Pyerpoint paused, then added, 'I hope I have done well to place my trust in you, Shom. Trust is an invaluable commodity. One ounce is worth a ton of belzite.'

Shom said nervously, 'I understand, sir. Your confidence is appreciated.'

Pyerpoint broke the link and sat back in his chair. The fingers of his left hand drummed anxiously on the desk.

A bleeper sounded from inside the desk. Pyerpoint pulled open a drawer and produced a small rectangular device that had a speaker built into the side. He pressed a b.u.t.ton and a familiar voice came from the speaker.

'Ah, Mr Spiggot. It's a lovely morning.'

Spiggot's hand was being shaken vigorously. Three seconds earlier he had been asleep, lying with his face immersed in the folds of the bounciest pillow that the station's launderers could provide. It took another few moments to identify the grinning loon that had shaken him awake. 'Er, good morning, Doctor.'

He sat up and pulled the silver sheets close to his naked form as he saw that the girl had also entered the room. Not that he had anything to hide from a woman.

'Hey,' he croaked, 'what time is this? I feel like a... like a...' He floundered for a simile as his hand stretched out, also searching.

Romana threw him a pair of briefs from a pile of clothes stacked at the other side of the room. 'Are you looking for these?'

The Doctor s.n.a.t.c.hed them away. He shook his head at the blue spotted pattern and handed them to Spiggot. 'I thought you were supposed to be in plain clothes.'

Spiggot covered his embarra.s.sment quickly and emerged from the bed. 'You two are the craziest pair I've ever seen Central put together,' he told them as he reached for more clothes.

Romana spoke. 'Perhaps we ought to explain. We're not from Cent'

The Doctor interrupted her, furiously gesturing for her to pipe down. 'Yes, well, what Romana means to say is that we didn't come directly from Central.' He leant conspiratorially close to Spiggot and whispered, 'Do you know, they didn't even give us a proper briefing.'

Spiggot raised an eyebrow. Held his gaze. 'They didn't?'

'No. Very irregular, I thought. So perhaps you'd like to give us details of our mission.'

Spiggot pulled his black sweater over his head and crossed to his cabin's food unit. He took a plastic cup and filled it with coffee, sighed a few times, took a few sips of the scalding fluid, walked back and forth, and then turned to face them.

'It started about two months back,' he began. 'Down on Five, one of the smart boys in the tech div labs picked something up.' He grinned. 'And that's pretty rare, I can tell you.' He waited for the Doctor and Romana to respond to his witticism but they only stared at him as if he had released a bad smell into the air and they were too polite to mention it.

'They were running a comparative systems check on their security computers using the system here. Nothing odd in that.

Except that it registered minor faults in the data core that backs up the Rock's security net.'

'What sort of minor faults?' the Doctor asked.

Spiggot sipped at his coffee again. 'Big ones. About as big as a minor fault can get before it becomes a major fault. In a nutsh.e.l.l, the security system at this place is cracking up. So far the damage hasn't advanced, but it could get a lot worse.'

Romana settled herself on a couch. 'Why didn't you just tell them and allow them to repair it?'

Spiggot pointed a long finger at her. 'There's the rub,' he said. 'I've got a contact down in the big smoke, worked in computers years back. He's pulled off a few frauds, but nothing too big. Deal is, I ignore him, he helps me when I need him.' He finished the coffee and crushed the cup. 'I guess we're both outsiders in a way.'

'Get on with it,' the Doctor urged. 'The computers.'

Spiggot decided to ignore the Doctor's rudeness. He probably couldn't handle the idea of a loner getting results by twisting the rules. 'Yeah, well, my contact is sharper than anyone in tech div. He can hack his way into deep compu-s.p.a.ce as easy as that.' To emphasize his point, Spiggot attempted to click his fingers but failed. Undaunted he continued.

'He took a look at the print-outs I smuggled out to him and said there was no way it was an internal fault. Someone was degrading the system. Someone clever. Someone more than clever.' He poured himself another coffee into another plastic cup. 'A genius.'

'Did you check up on the people here?' the Doctor queried.

Spiggot nodded. 'Every last one. None of them have form, but you'd expect that. Thing is, not one of the creeps has the nous to crash the system open. Whoever it is, we can't let 'em know we're on to them.' He took a huge gulp of the coffee.

'So I decided to come up here, to take a look about, on the quiet. But nothing seems to add up.'

'No, it doesn't,' the Doctor agreed. Suddenly he stood up and made for the door. 'Well, come on, Romana.'

The girl looked confused. 'Where exactly are we going?'

He stared at her as if she was a fool. 'To begin our investigations, of course. There's not a moment to lose.'

Spiggot stepped forward, worried. That wasn't the way he'd planned to use them. 'I wouldn't try computer control again, Doctor. Leave that side of things to me. I reckon you should just hang about, find out what you can.'

The Doctor fixed him with a manic stare. 'What, fade into the background, keep a low profile, listen out for vital clues, that sort of thing?'

Spiggot nodded. 'That'll do for the moment.'

'Good. We do that sort of thing very well, don't we, Romana?'

'Yes, I do, Doctor,' she said and led the way out.

Spiggot watched them depart thankfully. Things were going well. That pair of Romany crazies were fitting into his plan like they'd been part of it from the start. It was time to get on with the job.

He drained his coffee, crushed the plastic cup, checked his blaster, tucked it away in his jacket, and hurried out.

Pyerpoint switched off the listening device and replaced it in his desk drawer. He waited a moment, then snapped open a communicator channel.

'Computer control? This is High Archon Pyerpoint. I want you to carry out a deep systems check on the data core of the security net. Yes, you heard correctly.'

The Doctor and Romana entered the lift. As soon as the shutter was closed, the Doctor reached out and pressed a b.u.t.ton at random.

'Spiggot's playing some sort of game,' Romana observed.

'There must be a bugging device in that cabin. He wasn't talking to us but to Pyerpoint.'

The Doctor was lost in thought. 'Yes.'

'But we're playing along with him?'

'For a while.' The Doctor's huge blue eyes stared at the wall of the lift as if it was the most significant thing in the universe.

'We could always just go and have a look at the computer,'

Romana suggested.

The Doctor licked his lips. 'The computer?' he said gravely. 'Oh, I think there's considerably more at stake here than a machine on the blink.'

'Is there?'

The Doctor's mood switched suddenly. 'Yes!' he cried almost manically. 'Never overlook the elementary details, Romana.'

She groaned. 'Which elementary details?'

'Never theorize ahead of the facts, either,' he told her.

'First rule of detection. Besides, you're a bright girl, I'm sure you can work it out for yourself.'

The lift came to a halt and the Doctor breezed out. Romana directed her most venomous glance at his back and followed.

Spiggot pushed open the doors of computer control. Pyerpoint stood in the centre of the room, surrounded by a team of technicians. An animated display of the security net's data core, a twisting red cylinder, cartwheeled on the main screen.

It looked to be in perfect health. Spiggot nodded. A full inspection of each of the data core's four hundred and seventy-seven functions would busy the technicians for a tedious fortnight of processor checks and foreign program search and sweeps. His plan had worked out a treat. They were going to do this part of the job for him.

Still, he had to make sure he didn't let on. He put on his best look of surprise and disappointment. 'What's going on here?' he asked Pyerpoint.

Pyerpoint turned to him and said, 'A routine investigation.

It is standard procedure for the security net to be subjected to random examination, at the discretion of the station administrator.'

'Oh yeah?' Spiggot's eyes flicked over to the console where he had been apprehended last night. The keyboard was in pieces and a couple of technicians had their heads inside it.

He tried to look more upset.

'Is there any information you require from the net?'

Pyerpoint asked with a self-satisfied smile. 'I'm sure one of our people can retrieve it for you. Now that you possess full clearance, you have only to ask.'

Spiggot glared at him. 'That's all right,' he said bitterly.

'Don't trouble yourself' He turned his back on Pyerpoint and left the control centre.

Great stuff.

The observation dome was built into the roof of the station's highest level. An upturned bowl of clear plastigla.s.s with a circ.u.mference of a hundred metres, it overlooked the stars.

Each worker was allowed four hours' rest time in the observation dome per week, at periods allocated on the staff rota.

Margo had visited the observation dome only when a routine patrol took her there. The spectacle it offered did not inspire her. She took her satisfaction in writing reports and giving orders, and if her eyes ever did turn to the stars it was only to check that the asteroid's speed was as projected.

The dome's supervisor was therefore understandably surprised when she walked in alone wearing her plain white nightgown. He stopped himself from going to greet her. It was unwise to question the behaviour of an officer of senior rank, however strange.

He watched as she went calmly, in her bare feet, to the edge of the dome, put her hands to its side, and gazed out into s.p.a.ce.

Yes, there is Copralis, winking through the swirling dusts of the Vyl nebula; the reference point, at relative galactic the Vyl nebula; the reference point, at relative galactic coordinates eight five four nine south west by four six nine one coordinates eight five four nine south west by four six nine one north by north east. Planet Two is visible at a distance of north by north east. Planet Two is visible at a distance of about sixty-five million miles. It will be a simple task to about sixty-five million miles. It will be a simple task to confirm the station's relative position and speed and align the confirm the station's relative position and speed and align the homing signal. homing signal.

Margo shook her head and the inner voice faded. A jumbled group of algebraic figures were equating in long disused sections of her mind. But she knew nothing of advanced mathematics and possessed only rudimentary skills in applied astrophysics.

Her legs were quaking. She leant her head against the gla.s.s and tried to steady herself. Trickles of sweat were collecting in her eyebrows. The tips of her fingers felt hot.

Something made her raise her head. An impatience that seemed to come from inside, from the owner of the voice. It directed her eyes back to the star it called Copralis.

'Vectors at standard cruising speed,' it whispered through her lips. 'Correlated to the adjacent angle of velocity and accountable factors of stellar drift...'

The dome supervisor had left his desk. 'Chief, is there anything I can do for you?' he asked nervously. 'Chief?'

She snapped her head up. 'Fool!' she spat, a line of saliva dribbling over her chin. 'They are...' She put a hand to her head and howled at the stars.

'What's... happening... to me?' she wailed. She reached for her communicator. She had left it attached to her uniform, back in her cabin. 'Where... where...'

The supervisor flicked on his own communicator. 'Mr Shom,'

he called, 'please come to the observation dome. The chief is here, I think she's ill.'

The door of the observation dome slid open and the Doctor and Romana walked in. They stopped as they caught sight of the situation.

Shom looked nervously around computer control, but the technicians were too busy with their checks to have heard the call. Before he could reply, Pyerpoint put up a hand. He broke into the call. 'What's going on there?' he demanded, concerned.