Spiggot looked at him, confused. 'You have been away, mate. Ceerad. Stands for Cellular Remission And Decay. They were mutants, see. Escaped the purge of Vanossos and set up settlements on Six. Her particular talent was to crush people where they stood.' He pursed his lips and made a squelching sound. 'Over in a flash but very messy.'

Romana and the Doctor exchanged a glance that was deep with significance. 'Spiggot,' the Doctor said, 'I think you'd better tell us everything you know about this Xais.'

Stokes pressed a bag of ice on to his wound and winced. A couple of cups of tea, topped up with a dash of his favourite liqueur, had gone a small way toward the restoration of his spirits, along with the visions of Zy's likely humiliation and punishment that were pa.s.sing through his imagination. 'Oh yes,' he said with relish, adjusting the bag to tend to his throbbing brow, 'they'll spread you out and flog you until your bones squeak, my lad.'

The door of the gallery burst open abruptly and a group of guards burst in. They brandished blasters. Their leader, a young chap Stokes recognized as Shom, took a step forward.

'Stop right there!' he shouted.

'I wasn't intending to go anywhere,' Stokes said disdainfully. 'It took you long enough to get here. But then, I have come to realize that efficiency is the last thing one may expect from you gentlemen.' His eyebrows shot up as he noted Pyerpoint pushing through the group of officers into the gallery. 'The Great Sandshaker preserve us. This is a most unaccustomed pleasure.'

Pyerpoint stared at him. 'Stokes, I warn you, do not attempt to resist arrest. You will be shot if you try.'

'Arrest?' Stokes gasped. 'You dangerous and deluded old prune, what erroneous conclusions has your ageing intelligence brought you to now?' He gestured about him. 'I think you would be better occupied locating the miscreant responsible for this vandalism!'

Pyerpoint signalled to the men. 'Take him.'

The guards moved forward and took Stokes by the arms.

He stood still, almost unable to speak, his face gathering colour again. His mouth opened and closed a few times before he managed to say, 'Pyerpoint, you senile trout, I fail to see the slightest glimmer of logic in this action!'

The High Archon said gravely, 'Menlove Ereward Stokes, I arrest you for the murder of Efrik Zy. Anything you say will be taken down and may be used in evidence against you. You do not have the right to remain silent.'

Stokes was now totally perplexed. 'Zy is dead?' he said incredulously. 'But surely ' He took the bag of ice from his head and revealed the wound. 'Look at this. Listen, I've been quite insensible for the last hour at least.'

Pyerpoint turned to Shom. 'Take him to the detention area.'

'When the miners went in to Six the Ceerads weren't happy. A lot of them topped themselves. Some of them formed little armies. They didn't stand a chance,' Spiggot explained.

Romana was appalled. 'You're talking about genocide. An entire genetic strain wiped out.'

Spiggot looked unmoved. 'Don't get sentimental about it, dear. They were in a pretty sorry state. Probably better off dead.'

'I doubt it. Carry on.'

'Well, Xais got away from Six somehow. Pretty soon after, there were terrorist incidents on Five. Buildings, people.

Random attacks. Hundreds killed. The worst thing about it was what she left behind. Squelched stiffs.' He paused. 'The tech div boys reckoned there was something up with her genes that let her do people in just by looking at them. Some sort of impulse she could send out. An enlarged brain, and that meant she was pretty much a genius, too. Computers, bomb-making, an expert.'

'Then how was she caught?' asked Romana.

'They tricked her. Clamped a metal box around her head.

Then she was powerless. Put her on trial here, about three years ago, and she goes to the particle reverser. No surprises.'

He stubbed out another of his cigarettes. 'That should have been the end of it. Then, two months ago, a survey base was done in, on Planet Eleven.'

'I thought this system had been fully mined out,' said Romana.

'Not Eleven,' Spiggot explained. 'It's pretty small, and the atmosphere's too thick for a survey to be done from orbit. But with the recession on, the big mining corps can't afford to pa.s.s anything by. McConnochie Mining put down a base there at the end of last year and started to carry out a survey. Anyway, someone pretty clever waylaid their transmat beam, got in, killed their engineer and switched off the life support. Wiped their computers and transmatted out again. We thought it was pirates at first.' He grimaced and stared into the distance.

'Then we saw the body of the engineer. Squelched.'

Romana began to understand Spiggot's mission at last. 'So you were sent here to check up on the execution of Xais?'

'Uh-huh. I had to cover my tracks, 'cause the whole thing's secret. No one outside the force and the top bra.s.s at McConnochie knows about it. And, of course, in a case like this, n.o.body's beyond suspicion.' He picked up the file and weighed it in his hand. 'And there's no doubt about it. Xais fried three years ago.' He shook his head, looking puzzled.

'Looks like I've got a ghost on my hands.'

'It may interest you to know,' the Doctor said, 'that your ghost has struck again.' He related the story of Zy's death.

Spiggot sprang from the couch and started to pace up and down the room. Romana reflected that the carpet had probably not been paced over quite so much for many years. 'There must be a link,' the policeman said. 'Someone's found Xais's secret, I reckon. Worked out how to kill like her.' He nodded, resolute in this theory. 'And it falls to me to nail the creep.'

Romana put a sympathetic arm on his shoulder. 'I shouldn't worry, Mr Spiggot. You've got us to help you.'

He brushed her off 'Oh no, love. I work alone.' His features took on an expression Romana recognized from portraits of martyrs the Doctor had hung in the TARDIS power room. 'I can't get too close, see. It's what gets me results. If anyone takes risks, it's going to be me.'

The Doctor seemed to have lost interest in Spiggot's aggrandis.e.m.e.nt. 'A ghost, eh?' he mused. 'What do you make of that, K9?'

The computer had been listening to the conversation attentively. 'Existence of ethereal phenomena unproven, Master. Suggest corporeal explanation for anomaly.'

'Oh really? What explanation?' Romana knew that K9's ability to see things in purely logical terms had proved useful before.

This was not to be such an occasion. 'Cannot specify.

Insufficient data.'

'No, you never do know the answer when it's something important, do you?' The Doctor turned to the others. 'Let's go and find some more data, shall we?'

Spiggot's objection to their further involvement was cut short by a bleep from his communicator pad. The voice of Pyerpoint issued from the tiny speaker. 'Doctor, Romana, Spiggot. I wish to see you all in my office immediately.'

'We'll come straight away,' the Doctor replied. 'There's a lot to talk about.'

'I have already made the arrest,' Pyerpoint said. 'I require you to make a statement regarding your involvement in this matter.'

Romana was confused. 'An arrest? Who?'

'Stokes, of course,' said Pyerpoint. 'I shall expect you forthwith.' He broke the call.

Spiggot nodded slowly. 'Stokes, yeah, the artist guy, I've heard about him. And he had contact with Xais before her execution. She could have shown him a few tricks. Motive, means, opportunity. It all fits.' He appeared slightly disappointed that what had seemed only a few moments ago to be a challenging mystery had evaporated.

The Doctor stared at him incredulously. 'I wonder how you have ever succeeded in your profession,' he said. 'It doesn't fit at all. Not even slightly.'

6.

Nothing but the Truth.

The electronic bolts of the cell slid to and Stokes was alone.

It was a cell he had visited on several occasions in the course of his artistic endeavours, and contained in common with its fellows a low bed covered by grey blankets, a small and indecently public washroom cubicle, and a table and chair.

He sat on the bed and shook his big bald head. If he had been the kind of citizen that is more usually caught up in a miscarriage of justice, the sort with faith in the traditions of democracy and their application, he might have been prepared to sit and wait patiently until the facts became clearer and his release was a.s.sured. But Stokes had seen far too much of the realities of life in the judicial system, and what little regard he may have held it in had disappeared long ago. 'The illusion of freedom,' he would say to the few that still listened, 'is one of the luxuries of affluence. We are all prisoners to a greater or lesser degree, if we could but confront the fact.' In the more prosaic atmosphere of his present environment he was forced to review this p.r.o.nouncement.

'The trifling fatheads,' he spat at the walls of the cell. He looked up at the monitor camera in the corner. 'I hope you can hear me, Pyerpoint,' he shouted. let me say that if you believe in earnest that I was responsible for the demise of that wretched boy you must be several degrees closer to utter cretinousness than I had previously credited!'

The Doctor watched as Pyerpoint flicked off the monitor, unimpressed by the outburst. The old judge turned to face his party, who had just entered his office as instructed. 'Please be seated. I do not intend to detain you for very long.'

'Mr Stokes doesn't seem too happy,' the Doctor said as he settled himself into one of the uncomfortable straight-backed chairs.

'Mr Stokes is an immature and foolish man,' Pyerpoint said. 'Qualities that, ultimately, have led to this situation.'

The Doctor swung his booted feet up onto the desk. 'Are you sure about that? I hope you're not allowing any personal dislike to cloud your judgement.'

'Of course not, Doctor,' Pyerpoint said. 'I ' He broke off as he registered the presence of K9 for the first time. 'What is that?'

'K9 is one of Central's latest gadgets,' Romana lied. 'A police dog like no other. Fully equipped with reasoning intelligence, trillion plus strainer memory wafers and compatible sensor array.'

K9, obviously feeling rather grand, beeped importantly.

'Never mind about K9,' the Doctor said quickly, keen as ever to shine the light of attention back on himself 'I'd like to know on what grounds you've arrested Stokes.'

'This is an internal matter, Doctor, and need not concern you,' Pyerpoint said. 'Your involvement is limited to the fact that your colleague discovered the body of the victim. I should like you,' he addressed Romana, 'to make a formal statement on this matter.'

'I'll be more than pleased to,' she said. 'But it won't alter the fact that Stokes cannot have been responsible for the murder.'

Pyerpoint frowned. 'What makes you so certain of that?

The men were known to quarrel regularly. It appears that Stokes's gallery has been vandalized. I believe that Stokes followed Zy to the stairway. There, incensed with rage at the youth's destruction of his work, he bludgeoned him to death.'

Spiggot broke in. 'It comes back, sir, to my mission here.

See, it's a mite more complicated than I had you believe.'

'Oh?'

'There's something up with your computers, sure enough,'

Spiggot went on. 'Now, I can't really discuss the other matter, but I '

The Doctor swung his feet from the desk and bolted out of his chair. 'I've had enough of all this mystification,' he said angrily. 'What Spiggot is trying to say is that the murder of Zy resembles the deaths caused by Xais.'

'Xais?' Pyerpoint replied. 'Doctor, Xais is dead. I saw her die, three years ago. What can you mean?'

The Doctor leant over the desk and stared deep into Pyerpoint's eyes. 'Listen. You cannot treat this as a routine murder inquiry. Look beyond the immediate facts. What else but Xais's powers could have caused the injuries to Zy's body? Stokes wielding a length of lead piping? I hardly think so.'

Pyerpoint seemed unmoved. 'Doctor, the deceased is scarcely cold. A post mortem has been scheduled for tomorrow morning. Until the results are known, speculation on the cause of death can only prove unhelpful.'

The Doctor slammed his hands down on the desk. 'I've already carried out a post mortem, Pyerpoint. With K9.'

'That ridiculous dog thing?'

Romana sniffed. 'K9 is more sophisticated than any device your civilization will produce in the next three thousand years.'

'Never mind about that.' The Doctor punctuated the dramatic delivery of his words with precise movements of his hand. 'Pyerpoint, you must put this station on full alert.'

'I already have, Doctor. n.o.body from the lowest graded lavatory attendant to my fellow Archons can transmat away without my permission.'

'Good, good,' the Doctor said, only slightly taken aback.

'Now, release Stokes and get on with the real inquiry. Find out who has learnt to use Xais's powers.'

Pyerpoint raised his voice. 'As I have told you, Doctor, Xais was executed three years ago.'

'And as I keep telling you, Pyerpoint,' said the Doctor, 'somehow, somebody has learnt to kill in the same way.'

Xais opened the bottom drawer in Margo's cabin and withdrew the small device with the blinking green light. Built into the base were two switches. She pressed one of them. The device's emission of green light became constant. Excellent.

The signal had been received. All was proceeding according to her plan.

Perhaps it had not been good to kill the Normal on the stairs. The last few hours before the arrival of her partners were crucial and she could not risk drawing attention to herself. But then, the Normals believed she was dead. They would not connect her to the killing. And the temptation to kill had proved irresistible.

Soon there would be many more such deaths. She considered the prospect eagerly.

She raised a hand to her face and touched the mask. It felt cold and metallic, but the contours of her features were almost exactly how she remembered them from her first existence.

The idiot artist Stokes had done well, she thought. His finest work. She might allow him to live long enough to witness the beauty of his unwitting creation.

The stars glimmered through the porthole of the cabin. The streams of equations that lay scattered about the room had proved to be correct. She had calculated the exact position of the Rock, and beamed the homing signal along a chain of pirate satellites that led out of Uva Beta Uva into other systems. Now the time had come for the next stage of her operation.

There was a problem. The computer defences of the Rock would have to be dealt with. There was a risk in removing the mask, but she had to reach the control centre unchallenged and there was no other way. And soon, she thought, there would be no need to remove it, until the host body was exhausted. Until full activation had been achieved.

She pulled the mask from her face. The slight psychic shock awakened a trace of Margo's dormant consciousness.

What's... what's happening to me?