Although Senile Nine had been denied wealth through tourism, it now grew rich and fat on the production of what became known as Mosten's acid.

The Doctor knew the history of the acid he carried in his pocket, but he was not thinking about it as, with Azmael, he made his way along the corridor. He was more worried by the lack of guards. It made him feel uneasy. Mestor might be all powerful, but even he would take some precautions.

As they waited for the ma.s.sive steel doors to the throne room to swing electronically open, it was Azmael who supplied an answer to the Doctor's concern.

'If you were Mestor, and you knew that I knew what you planned for this planet, would you want to discuss it in front of Jacondan courtiers and guards? Personally I would think you would prefer to keep it all rather private.'

As they entered the long, dank, sepulchral throne room, it seemed that Azmael was right. Apart from the ma.s.sive, s...o...b..ring form of Mestor, slouched on his throne, the room was empty.

Cautiously, the two Time Lords started the long trek towards their captor. As they walked, Azmael noticed that ma.s.sive humidifiers had been installed and that each one was saturating the atmosphere with an ultra-fine sheet of water. Everything dripped including the beautiful tapestries which adorned the walls.

But what broke Azmael's heart most of all were the thick layers of petrified mucus which encased the mosaic floor. A thousand years ago it had taken Jacondan artisans ten years to create the fascinating and intricate patterns of the mosaic. Such was its final glory that it it had been declared an ancient wonder of the Trilop Major galaxy.

Now it was ruined, destroyed beyond restoration, and the s...o...b..ring ma.s.s which sat upon the marble throne before them didn't care at all.

'Long walk,' said the Doctor flippantly. 'And now I'm here, 1 don't think the sight of you was worth it.'

Mestor moved uneasily in his chair. In spite of his earlier conversation with the Doctor, he was still unaccustomed to being spoken to in such a rude, offhand manner. 'Control your arrogance, Time Lord,' he rasped.

As the Doctor had only seen and heard Mestor via a hologram projection, he was surprised by the deepness and richness of his voice. Gone was the marked sibilance and slight cackle the hologram had created. Gone, for the time being, was the melodramatic postering and ranting.

Yet none of these small refinements did anything to compensate for meeting Mestor in the flesh. From any point of view, he was disgusting. And what's more, he stank.

The Doctor hoped they could conclude their business as soon as possible and be gone. The throne room wasn't a pleasant place to be.

'Look, Mestor, Azmael and I have worked out what you're up to and it's got to stop!'

The gastropod gave a small, involuntary laugh, then belched. He suddenly found the Doctor amusing. It took courage to threaten Mestor in his own throne room, and the gastropod was mildly t.i.tillated by it.

'Are you listening to me, Mestor?'

The gastropod belched again.

'You'd better be!' The Doctor sounded more like a street bully than a Time Lord negotiating with a creature capable of taking over the universe. 'Because I'm not having your sluggy eggs spread all over the place, causing havoc. Do you understand?'

He understood perfectly, but there seemed little point in taking any notice. 'It seems that you are not only mad, but a buffoon, Doctor!'

This didn't please him at all. 'I'm warning you. Will you give up this nonsense?'

'No, Time Lord.'

Then take the consequences.'

Briskly, the Doctor removed one of the flasks of Mosten acid from his pocket and threw it at Mestor. But he wasn't fast enough.

Instantly a blue barrier of energy surrounded the gastropod and the flask smashed harmlessly against it.

As the barrier faded, Mestor growled. 'You think that I would be so vulnerable?'

The Doctor shrugged. What could he say? He had failed.

'I thought, Doctor, that you would be interesting to know. But like so many humanoid life forms, you are totally preoccupied with your own pettiness.'

Carefully Mestor altered his position. He found it difficult to maintain the same posture for long, chairs being unnatural for his body shape.

'I think it's time I dealt with you, Time Lord.'

'Please, Lord Mestor,' pleaded Azmael. 'The Doctor has been ill.

His mind is muddled. It's affected his reasoning. I'm sure, with rest, he will learn to appreciate the respect due to you.'

'He has tried to kill me. He must therefore forfeit his own existence.'

While Azmael continued to plead for his friend, the Doctor glanced over his shoulder and wondered whether he could make it to the door before Mestor had time to unveil another of his tricks.

The thought of dying didn't very much appeal to him. But to be murdered by a slug with pretensions way beyond its cabbage patch would be too much.

'I said, Azmael, that the Doctor would cease to exist. I did not say he would die. If I were to kill him, how would I be able to take over his body and mind?'

The Doctor let out an involuntary sn.i.g.g.e.r.' You take over my mind. It would be like throwing a pebble into a lake. It would sink without trace.'

'Please, Doctor. The Lord Mestor is quite capable of doing what he says,' said Azmael.

'A Jacondan mind, perhaps. But I am a Time Lord.'

Mestor laughed loudly, this time without managing to belch.

'Perhaps you would like me to demonstrate how feeble a Time Lord's mind really is?'

As the question was a rhetorical one, Mestor did not wait for an answer. Using nothing but pure thought he operated a control built into the arm of his throne. Suddenly Mestor was shrouded in a green, ethereal light. Then without warning, a vicious, luminous green finger of concentrated energy shot out and locked on to Azmael's forehead.

The elderly Time Lord screamed.

This wasn't what the Doctor had expected. But then Mestor was rarely predictable. That's how he managed to survive.

As the Doctor continued to watch, a small black blob seemed to work its way along the finger of light.

As it reached Azmael's forehead, the blob spread across his face, then slowly it began to permeate the skin. A moment later it was gone. Mestor now resided in Azmael's brain.

As the green light faded, Mestor's body collapsed, lifeless like the skin of a snake when sloughed. Concerned, the Doctor rushed to his friend. 'Are you all right?'

Azmael started to work his mouth up and down, like a ventriloquist's dummy, but nothing came out. When words finally did emerge, it was not Azmael's voice, but Mestor's that he heard.

'Azmael is now my slave. I have taken over his mind.'

That's not fair. He's an old man.' The words sounded foolish, almost childish, but then the Doctor wasn't used to seeing physical transference of one creature's mind to another.

'I could do the same to you, Doctor.'

'Then prove it!'

The face of Azmael sneered. 'All I need is...' but Mestor didn't finish the sentence. Instead his voice faded, Azmael's pained and agonised voice replaced it.

'He's weakening, Doctor. Mestor is attempting to control too much... All Jaconda is affected with his thoughts.' Azmael paused, his body heaving with the effort of controlling the unwanted presence in his mind.

'We must mind-link,' insisted the Doctor. 'Together we can destroy him.'

'No!' The voice sounded more agonised than before. 'He will pa.s.s to you, and you will be lost.'

'I can contain him.'

'I may be old,' croaked Azmael, 'but my experience in mind control is greater than yours. You must destroy Mestor's body, otherwise he will attempt to return to it.'

But how?

The Doctor's experience in dissecting two metre long slugs was non-existent, although he did recall having once read that the garden variety could be destroyed by covering them with sodium chloride. But where would he find enough salt?

'Hurry, Doctor!' screamed Azmael. 'I cannot control Mestor for much longer.'

Suddenly the Doctor remembered the second flask of Mosten acid and set about searching for it in his cavernous pockets.

The Doctor was angry with his lapse of memory. He had wasted valuable time. Azmael had been right to warn him against taking on Mestor. In spite of his vast improvement, the Doctor's regeneration was far from complete.

Finding the flask, he moved to the gastropod's moribund carca.s.s and emptied the contents over it.

The response was immediate. Huge blisters began to form on the moist, oily epidermis which then burst, scattering dry clouds of flakey skin. At the same moment, the corpse started to sag and fold in on itself as though a large invisible weight was pressing down on it.

As the dehydration process continued, Mestor's spindly limbs snapped and powdered like old paper exposed to a sudden gust of wind. Then his face dissolved into thick chunks of heavy cardboard which crumbled, yet again, into dust.

A moment later, all that was left of the Lord Mestor was a pile of fine grey dust, not unlike the ash of spent charcoal. The Doctor turned to Azmael. 'It's done,' he said quietly.

'Too late, Time Lord!' It was voice of Mestor. 'I now completely control your friend's mind.'

But he had spoken too soon.

Suddenly the body of Azmael began to sway, then reel like a drunken man. 'What's happening?' roared Mestor.

There was a pause, then the strained, agonised voice of Azmael was heard. 'You're dying, Mestor. I'm doing the one thing you cannot control - I am regenerating!

Again, the voice changed and Mestor started to rant and shout.

The Doctor turned away, angered and frustrated that he could do nothing to help. The mortal battle which was taking place inside his friend's mind was one that could only be fought by him alone.

To interfere could prove fatal.

As Azmael struggled to stay upright, he staggered and wobbled about the room. But even with the wall as support, the effort proved too much and he collapsed.

Horrified, the Doctor rushed to the crumpled heap. 'You can't regenerate,' he pleaded. 'You've used up your allotted number of lives.'

Summoning the last of his energy, Azmael forced a smile to his lips. 'Do you not think I know that?'

As he spoke, a black, amorphous stain seemed to swirl and spread under the skin of his forehead. For a moment, the Doctor thought his friend was experiencing a ma.s.sive haemorrhage.

'Do not be afraid at what you see,' said Azmael. 'It is all that remains of Mestor. He is trying to break out, evacuate my dying frame.' The strain grew into a pulsing blob. 'But he won't succeed.

I can sense his strength is failing.'

Azmael began to cough tiny specks of blood. 'He is finished.'

Then slowly, almost imperceptively at first, the blob began to shrink. Somewhere, in what sounded like the distant depths of time and s.p.a.ce, a ghostly scream was heard. It was Mestor.

'Why did you regenerate?' said the Doctor sadly.

'I had no other choice.'

'We should have mind-linked. Together we could have defeated him.'

Again, Azmael coughed, but this time blood flowed freely from his mouth. 'My friend, you are too unstable. He would have swamped you... You would have been the pebble drowning in his lake.'

'But to throw away your life ...'

Azmael smiled for the last time. 'It was nearly over.' He paused, the effort to talk was proving very painful. 'My only regret,' he panted, 'was leaving Gallifrey when it needed me most... To become a renegade is to give up one's roots...'

The Doctor nodded, knowing only too well how he felt.

'But still, my friend,' the voice was even weaker, 'I did try to do my best for Jaconda...'

Azmael started to cough violently, the rattle of death apparent. The old man was fading fast.

'Jaconda certainly gave me a good life... Many great moments.'

The words were separated by violent gasps for air. 'But one of my best... was that time by the fountain... my friend ...'