I know your weaknesses, Doctor. You forget, your mind is pitifully open.

'This creature can read your mind?' Tom was astonished.

'It is is my mind At least partly.' The Doctor did not meet Tom's eye. 'It's routing its power through the TARDIS' telepathic circuits.' my mind At least partly.' The Doctor did not meet Tom's eye. 'It's routing its power through the TARDIS' telepathic circuits.'

Bernice was struck by a thought. 'What did you do with the cross-check circuit you were talking about? The link with Ace?'

The Doctor put his hands behind his back and looked a little shifty. 'There was one?'

'Yes! You put a telepathic link into her mind, and the TARDIS wouldn't trust you, only her. You have a very convenient memory sometimes.'

'And so does the TARDIS.' The Doctor glanced up at the blur of the Time Soldiers, as if wondering how much he dared say. 'I was reconfiguring while we were in Oxford some of it in unorthodox ways. That circuit was one of the first to go. I smashed it.'

'You did what what?'

'Don't worry. It's all been selective, constructive vandalism.'

Bernice looked horrified. 'I thought you were trying to realign the TARDIS with the old pattern. Well, the new pattern. You didn't tell me you'd taken a hammer to the poor thing!' She shook her head in despair. Only the Doctor, she thought, could get himself into so much complicated trouble during what had been, for her, an absence of less than a few hours. It was suddenly brought home to her, in a sudden, shocking jolt, that a whole multitude of happenings in other places and times could have separated the Doctor's departure from Oxford and his reappearance in the President's TARDIS. And he still hadn't really explained what he'd done with Ace. Benny was not even really sure she wanted to know.

The Doctor shrugged. 'I had other things on my mind. Besides, destruction can be a dynamic force. And you only perceive it with hindsight.'

'So ' Bernice looked from the console, to the Doctor, to the incandescent Time Soldiers The implications of the Doctor's action were simmering in her mind She could feel that when they came to the boil, someone or something was going to get hurt. She decided not to put the question she had been considering, and instead asked, 'So where are we going?' She received no answer, and slumped back into the chair with a sigh. She glanced at Tom. 'Doesn't all this make you wish you'd read Sociology instead?'

Your efforts mean nothing, Time Lord.

The Doctor glared defiantly at the lights above the console. 'We're not finished yet, Garvond. Don't fly too near the sun.'

It was then that Bernice felt a familiar chill grip her as the sound she had heard in Oxford rippled through the console room. Twittering, like a thousand angry birds in a cavern.

And with the sound, the time rotor began to slow.

Rafferty and Terrin hurtled down the path towards the black Porsche, ignoring the stares from the pub terrace.

The police constable a real one this time who had been hovering by the car for the past ten minutes looked up expectantly as the two men careered towards him.

'Now then,' he said, poised to pounce. 'Which of you gentlemen is the owner of this vehicle?'

Rafferty and Terrin glanced at one another. The Professor was uncomfortably aware of their eccentric appearance.

'It's mine,' said Rafferty. 'I, ah, didn't realize this was a no-parking zone. Terribly sorry.' He shrugged, and gave his best after-dinner smile. He was aware that Terrin was slipping round the other side of the car. Please, James Rafferty was thinking, just let the door be open. I'll do anything as luck's payment. Even the first-year calculus revision class. Even another Faculty drinks party.

The policeman sighed. The look he gave Rafferty was a mixture of disdain and despair as he unfolded his notebook. 'Name, sir?'

'Look, tell you what I'll get my licence. It's in here.'

And he grasped the handle of the jet-black door.

In less than a second, the policeman had seen the twin flashes of movement. The door slammed in his face. He hammered on the tinted window, shouting angrily. Then he straightened up.

Lateral thinking, he said to himself, with a smile on his face. That was what the Sarge always said. They couldn't sit there forever.

He grinned at the setting sun.

It was reflecting very beautifully in the car's glossy exterior. Nice looking motor, he thought in approval. Shame it's driven by a joker.

He was still engrossed in such thoughts when a mechanical screeching began to emerge from the car's bonnet. Shocked, he took a step backwards.

A few seconds later, it was perhaps fortunate that there were no witnesses to the young constable's expression.

Tension hummed in the Doctor's TARDIS. The Doctor, pacing around the console with his hands clasped behind his back, paisley handkerchief trailing from one finger, would occasionally glance up at the still time rotor, and then at the nimbus above it. Each time, his expression showed deep contempt.

'Doctor,' Tom asked, 'what are we doing?'

'Waiting,' said the Doctor. 'For a signal.'

Tom slumped back into his armchair. 'Why does it need to wait?' he muttered.

'Perhaps it's tea time,' Bernice suggested. 'I could murder some scones myself, actually.'

The Doctor had directed his unnerving gaze at Tom once more. 'I doubt there'll be honey still for tea. No jam either, not today, not tomorrow. Never, with the Garvond.' He rounded the console till he was level with Tom, and narrowed his eyes as he looked down at the young man. 'Myself, I'm fond of almond slices. I don't have much time for anyone who doesn't like almond slices.'

'Oh, I adore them,' said Tom somewhat uncertainly.

'Of course you do,' said the Doctor, whose tone had not changed. He straightened up and resumed his circling of the console. The nimbus throbbed for a second, then resumed its shimmering. Shadows grew in the corners of the console room. 'Of course,' the Doctor continued, to no one in particular, 'toffee is the most useful confectionery for analogies. Have you ever seen a mechanical toffeemaker?' He whirled round to face them, looked from one to the other. Bernice and Tom appeared equally bemused. 'It stretches the toffee in one direction,' the Doctor spread his hands wide, 'then slaps it together again.' His palms came together with a resounding smack. 'Then it stretches the two-layered toffee,' he said, his eyes wide and bright, the Time-energy nimbus reflected in them. Bernice was beginning to wonder if the Doctor had spent a little too much time indoors on his own recently. 'And so on,' he concluded, gripping the edge of the console with both hands. 'And if you have sufficient resources and sufficient stupidity you can do the same with Time. Points which start close together can end up far apart. Aren't you familiar with Smale?' This last comment was thrown at Tom.

'Of course,' the young man said, relaxing a little at the mention of a mathematician whose work he had studied. 'The chaos of dynamical systems. Squeezing and stretching space until you're left with something multi-layered and unrecognizable...' He broke off, going very pale. 'Doctor, are we going to stop this?'

'It's possible,' said the Doctor darkly. 'But if you want the right answers, you have to learn to ask the right questions.'

'Or vice versa,' Bernice put in.

The Doctor glowered at her. She smiled placidly back. The non-verbal exchange could have meant a multitude of things, and Bernice, behind her smile, could tell they weren't going to get many of them sorted out much before this was over.

The familiar twitterings of the Time Soldiers filled the console room. As they watched, the nimbus grew to a dazzling intensity before splitting into two Time Soldiers once more. Almost solid, they hovered above the console like angels of death, then slowly floated to the floor, their red eyes glowing with hate.

Above their restless noise came another sound, which for Benny was even more familiar: the low hum of the TARDIS doors opening.

Vaiq was sitting in her office, with her hands curled round a chilled glass of fruit juice.

Her intercom buzzed. Wearily, she took the call. 'Vaiq here.'

'Helina?' The voice was that of Ballantyne. 'You're never going to guess what we've detected.'

'Surprise me.' Her head was aching again. She closed her eyes briefly, and saw images of fire.

'It appears to be a rogue energy source. Approaching, but not on any scheduled flight path. And if I were you I'd come to the control centre, because there's something else I'd very much like you to explain.'

Something told Helina Vaiq that the Doctor's words were about to start turning into reality.

'Look!'

The voice was Cheynor's. As Ace, Strakk and one or two others leapt to their feet, the Time Soldiers clustered defensively around the oblong shape that was forming next to the Garvond's throne. Their blasters covered a wide arc. Ace swallowed.

Silent, veiled in green light, the TARDIS shimmered into solidity on the bridge of the Survey Ship Icarus Icarus.

Ace's fist clenched at her side and something welled up inside her, a mixture of dread and excitement.

'He's here,' she said. 'The Doctor's here.'

As the glow faded from the TARDIS, the Garvond gave a deep-throated roar of triumph. It billowed through the clouds of Time and shook the bridge, and they felt it rock the floor beneath their feet.

Bernice was the first to emerge. She shoved her hands into her pockets and sniffed. 'Bit stuffy in here.' She glanced around. 'Hello, Ace. Glad to see we haven't mislaid you.'

'Yeah. Cheers.'

'You know this person too, right?' was Strakk's contribution.

Tom was behind her. He stopped, blinked a couple of times. 'Oh, well,' he said eventually, in a very small voice. 'In for a penny...' He stepped out on to the podium, giving the Garvond very nervous glances, before he descended to the main floor of the bridge.

Darius Cheynor's incredulous gaze had been on him from the very first second.

The Doctor had emerged. He nodded to the Garvond. 'Oh, very pleasant,' he spat in its general direction. 'Very theatrical. Only a couple of millennia out of date with your cultural references, but not bad.'

He looked around the room. Ace hoped he was seeing what she would. Tiredness, hunger, the hostage look. Faces of people coming to terms, people getting a grip. She hoped the Doctor appreciated it all, what people went through.

There was silence on the bridge, except for the distant thunder of the engines.

The Doctor descended the Captain's podium and none of the Time Soldiers stopped him. He nodded to Strakk. 'Lieutenant.'

Strakk acknowledged him wearily. 'Hadn't forgotten you, Doctor.'

The Doctor gave a smile as dazzling as it was brief. 'Sorry I couldn't return the favour.' He turned to Cheynor, who was still staring intently at the third occupant of the object that had materialized on his bridge. 'Acting Captain Cheynor, I believe. Captain Terrin sends his regards.'

Cheynor's eyes widened. 'You mean...?'

The Doctor nodded silently.

He looked at Ace. She could sense he was trying to read her again, to see her reaction to this latest reunion. 'We have to go on a journey,' he said softly.

It was perhaps unwise that Ace chose that particular moment to look over the Doctor's shoulder at the looming skull of the Garvond.

And remembered the darkness.

Falling, with the Doctor standing over her.

'Yeah,' she said, and the inside of her mouth felt dehydrated. 'Tell me about it.'

All eyes were on the Doctor. He turned, slowly, to face his adversary.

'So,' he said, 'here I am at last. We have had fun and games, haven't we? There must be simpler ways. Couldn't you simply have challenged me to a game of chess? Or ping-pong?'

You over estimate your own importance, Doctor.

'I think not.' The Doctor had somehow gained a radius of floor-space around him. Ace realized he had done it again. That great attention thing. He leant on the dome of the tracking console and met the Garvond's empty stare. 'Remember, there is some corner of a Garvond's field that is forever ' The Doctor tapped the side of his own head. 'Doctor.'

The Garvond's hiss was electric. The three nearest Time Soldiers blazed dangerously in harmony with their master's anger. Ace met Benny's gaze across the bridge. She knew they were both thinking the same. If he pushes it now 'I thought I had put right my error,' said the Doctor softly. 'I broke a rule, but then you know that. A rule that no other Time Lord dared break. Or at least I will. Will have done. And I erased my own print from the Panotropic Net in the Matrix.' He drew breath. 'I knew you'd come. A creature of legend, oh, but so true. So real. Ever since that time I saw the Ancient Law Ancient Law, back when I was dealing with that Skagra business. I saw my part in your creation and I destroyed you and I destroyed you!'

Something very odd was happening to Tom Cheynor.

The Garvond's breath was like audible fire, like the clouds gathering before an electric storm. It grew in size and brightness, its throne filling the black globe and rising now, like a bubble fighter than air.

The humans cowered. Even Ace, trying to stand her ground, felt her feet pull away. She saw the shattered skull in her mind again, heard the screams and the exploding of bone after bone. All life, all death, passing in an instant. With power unimaginable.

She felt an arm steal round her waist. It was Strakk. Whether giving comfort or seeking it, she did not know. She held him anyway.

You may have thought me destroyed, once. The Garvond's voice was like clashing rocks, booming in an underworld where demons rose from ancient sleep. The Garvond's voice was like clashing rocks, booming in an underworld where demons rose from ancient sleep. But now... I am reborn! But now... I am reborn!

Tom Cheynor had turned to face them all.

'Doctor!' Bernice cried. 'He's '

'The Time Focus,' the Doctor growled. 'Back! Everybody back!'

The TechnOps needed no second bidding. They surged away from the looming Garvond.

As they watched, the creature gathered itself like a cloak of night, its bubble distorting into a new shape. A finger of fire and darkness reached out towards the crowd of humans. And then, in one sudden inrush, it happened. A javelin of black light hit Tom between the eyes and he stiffened in silent pain. For a second, his body was surrounded by a halo of possession, the time energy's deadly sparkle.

No longer under its own control, the body of Tom Cheynor turned to face the assembled crowd. His eyes were burning with green fire. There were lines around them. Lines etched by age and pain which had not been there before.

The ships of Time. The Garvond. And the Focus. The parts were all assembled, the power surging into the Vortex. Detonation was imminent.

Surrender, Doctor.

The mouth which moved was Tom's. But the voice was still that of Garvond.

The control centre of Station Q4 was filled with the babble of TechnOps and the hum of holo-units.

Helina Vaiq blinked when she saw the two figures standing with Ballantyne on the other side of the Itopian Helix display. One she recognized as Romulus Terrin, looking slightly more controlled but also more haggard than when she had last seen him. The other was an extraordinary sight. The striking, intelligent face of a fit-looking man in his fifties was rather undermined by the outlandish clothes he was wearing a black costume with a butterfly-shaped tie at the neck, adorned with what appeared to be a broad and baggy-sleeved black cloak with a fur hood. The man, whose arms were folded, glowered at her defiantly as she looked him up and down.