He guided them down a string of pathways and several sets of spiralling iron stairways to ground level.

Rhun greeted and introduced people as they went.

Apart from the native Australian's who inhabited the cavern, the remainder of the population were generally scientists or inventors who wished to pursue their projects without any government to misuse their genius.

'A ready-made rebel alliance ... just what you need, yes?' he asked his two honoured guests, already knowing the answer. 'You see, when the time came to hand over the rule of Gwynedd to Cadwell, I decided to do a little time exploration of my own ... well, actually, Taliesin insisted on it. The High Merlin took me shopping in the year 2035 AD, and much of what you see here is a direct result of that journey. This series of caverns, though already naturally existing, were extended, moulded and fortified using a combination of bacterial quarrying and organic cementation, a process that will not be perfected for a least another fifteen years.'

'Wow.' Rhiannon didn't really have a clue what he was on about, but it all sounded very impressive.

Passing through a huge triangular opening in the wall, they followed a wide thoroughfare into a second cavern that was even bigger than the last.

' Food,' Rhun announced to answer one of his mother's questions as he escorted them over a large bridge. 'This is the hydroponics and farming centre of our little community.'

The moat that encompassed the circumference of this cavern was sectioned off for the farming of various species of fish and molluscs; large greenhouses were filled with all manner of thriving vegetables and herbs, whilst the exterior gardens, and orchards of fruit, were host to small livestock, such as chickens, ducks and geese.

'To graze cattle or sheep here is out of the question, so we mainly stick to seafood, fruit and vegetables, although we do keep some cows and chickens in the large barn yonder, for dairy goods and eggs. The Aboriginals tend to go their own way with their food, so everyone is also free to cultivate what they please. The more nationalities of people who end up here, the more diverse our diet is becoming.'

Tory was turning circles trying to comprehend everything that was going on around them. People were harvesting, planting, pruning, picking, fishing, feeding, watering and just plain relaxing. 'But how on earth do you generate enough power for all this?'

'Natural gas, or you could say, shit,' Rhun informed them simply. 'It's a Sakahauchi methane processor, first developed in America with moon colonisation in mind.

This also supplies us with water and fertiliser for agriculture, whilst addressing the sewerage problem at the same time.'

'You are far too clever.' Tory gave him a huge hug as they approached the far end of the farming cavern. 'I am impressed beyond my wildest expectations.'

'Where does this lead?' Rhiannon was poised ready to race off across a bridge that crossed over the moat to yet another thoroughfare through the cavern wall.

'Why don't you find out?' He gave her leave to go on ahead. 'I have a present for you,' he advised, putting his arm around his mother's shoulders.

'Through there?' Her eyes motioned to the tunnel Rhiannon had disappeared into.

'You guessed it.'

'Oh Mother, quickly.' Rhiannon bolted back to wave Tory on. 'Wait until you see this. You won't believe it!'

This final cavern was the largest of the three so far and contained several enormous pools of water.

Natural sunlight poured in through a hole in the roof at the far end.

Rhiannon headed towards the boat ramp and a tool shed at the side of the largest body of water.

As Tory stood staring at her saving grace, he leant over her shoulder to whisper, 'The universe always provides.'

She gripped his hand, appreciative of having at least one of her major problems solved. 'Now all I have to do is figure out how to get the Goddess here.'

'What do you mean?' He was surprised at her. 'Just will it here.'

Tory burst into laughter. 'Something as complex and huge as our craft? I don't think so.'

Rhun shook his head, emphasising his disappointment. 'You haven't been developing your abilities, have you?' His scolding expression melted into a confident grin. 'Well, it's a good thing for you that I have.'

'What?' Tory thought he was surely joking.

'I can get her here, crew and all.' He shrugged. 'All you need do is take me to her.'

'Well, let's do it!' Tory clutched both his hands.

'Settle down!' Rhun was amused by her eagerness.

When he'd last seen her it was he who was the impetuous one, but now it seemed just the reverse was true. 'There is someone you really must meet first.' His mother still seemed a little anxious, until Rhun assured her, 'Your vessel is fine for the moment, so indulge me a while longer.' He offered Tory his arm, which she took with a smile.

On the way back to the cavern of abodes, Rhun told the story of how he and Pete had come to found this colony.

By 2035 the Earth was well and truly feeling the effects of the tilt of its axis. The slow magnetic reversal resulted in a weakening of the Earth's magnetic field, making the planet more vulnerable to strikes by meteorites, comets, and exposure to cosmic rays. A nuclear air blast, triggered by terrorists, ripped a huge hole in the ozone layer in 2020, creating erratic weather conditions which wreaked havoc on the world's food supply.

A huge supernova flare had been predicted for the year 2037. It could increase the already unbearable levels of radiation to the point where the Earth was uninhabitable. Rhun hadn't stuck around long enough to find out whether this came to pass, but by the time he had left, those with the money to pay their way had already started heading for the moon colonies, leaving others to inherit the Earth.

Many years before Rhun departed, the climate in the Red Center had begun to change, returning the desert to the tropical oasis it had been long ago in Gondwanaland.

As more and more resorts took advantage of the climate change and sprang up around Uluru, Watarrka and Kata Tjuta (the Olgas), the Aboriginal people were robbed of their tribal lands. Of course, they did not take this lying down and the resultant bloodshed could only be compared to the first white invasion of the territory, way back in the early 1800s.

'But what brought you to Australia?' Tory wondered.

Rhun shrugged. He'd had no option. 'In less than twenty years, Australia will be a major super-power, and some of the most outstanding technology will be designed and produced in this country. This was where I first met Pete Nangina, in the future. A bitter old bastard he was too, resentful and angry at all white men for the dwindling numbers of his people. In fact, the only reason he spoke to me at all was because he discovered he couldn't kill me.' This memory made Rhun smile. 'Once I told Pete my history and why I had travelled to his time, and of my plan to return to the late twentieth century, we began to see a way we might be able to save both our peoples from the holocaust ahead. He wrote down an account of the injustices that would befall his people, which I brought back to Pete Nangina in 1999. After the first two of the said disasters came about, I was taken to the tribal elders to put forward my plan for this place.'

This particular site had been selected for several reasons. Watarrka was government land and a tourist attraction, so there was no chance of their little community ever being built out or mined. The majority of the park rangers were native Australians, who could do a fine job keeping people away from the place. But the real deciding factor had been that, during all of the Earth's natural disasters, this part of Australia had remained the least affected area on the planet.

'Since the day our alliance was formed, many of the tragedies that Pete Nangina predicted were, if not avoided altogether, very much delayed and their consequences less harsh,' Rhun was pleased to boast.

'So you and Taliesin have altered the future yet again.' This made Tory uneasy, but who could really say if it would be proven good, bad, or indifferent?

'That we have.' He paused 'For, in an alternative future, you, Taliesin, and father decided it would be best.'

This must have been the same time that Tory's future self had decided to go back to the Dark Age to advise herself to conserve the life-giving potion that had subsequently saved Brian's life. So, if the future was now on a different course, did this mean Tory no longer had to make that journey, because she would still carry it out in some other inter-dimensional reality? She gave up thinking about it. 'Where is Taliesin now?'

Rhun shrugged, resuming their course. 'He returned to Gwynedd years ago to see to the higher education of Cadwell.'

'Speaking of whom?' Tory pulled Rhun up again, hoping to solve another of her life's riddles. 'At what age did Cadwell assume his immortal state?'

Rhun gave a heavy sigh as he recalled the most fearful moment of his parenting life. 'He took a bad fall from a horse at five years of age ... luckily, I was the only person present.'

'And your grandson?' Tory urged, as gently as possible.

'Cadfan ...' Rhun smiled, proud of him.

'Alias, Walter Cadfan?' Rhiannon finally got a word in.

'The same.'

'I knew it!' both women exclaimed at once.

'So, although I was not in Gwynedd to witness his physical death,' Rhun qualified his next words, 'Cadfan told me, when we bumped into each other here, that he first died in a freak accident, aged twelve and a half.'

'And Taliesin tutored him?' Tory knew this must be so, as Cadfan had seemed an enlightened soul.

'And Cadwallon, after him.'

'What about Cadwaladr?'

Rhun had been wondering the very same thing himself. 'Your guess is as good as mine.'

They scaled the pathways and stairs leading to one of the highest caves in the cavern, and Tory was surprised to hear a favourite song from her youth wafting from their destination. She mouthed the words to the tune a moment to recall the artist. 'My God, you know I haven't heard Pink Floyd in over ten years!'

Rhun laughed. 'You know them? Floyd will be impressed. That's how he got his name, or rather ... his handle. Open,' he instructed, and the door vanished to disclose a room full of computer monitors, processors and a vast array of accompanying hardware.

A middle-aged man was slouched in a seat, his crossed feet up on a bench. He was singing along with the stereo as he happily puffed on a very large joint.

'Hey, Floyd!' Rhun yelled for his attention.

'Woe, excuse I.' Floyd turned down the volume, stubbed out the joint, and swivelled around on his chair to make their acquaintance. 'You must be she?' He put on his little, round, wire-framed glasses to get a better look at Tory.

'Must be.' Tory held out her hand to shake his.

She'd been wondering how long it would be before her old champion, Sir Tiernan, showed up in the twentieth century. He had a radically different look now, in his Grateful Dead T-shirt and ratty old jeans. A beard and moustache hid his handsome face and his fine, fair hair fell halfway down his back. Tory imagined that when he wasn't so stoned, his eyes would be the same gentle blue she remembered Tiernan having.

Floyd gently took hold of the legend's hand. 'This is truly an honour. I've heard so much about you.' He pointed to Rhun as his source. 'It is wonderful that you are finally here amongst us.' Floyd's attention drifted to Rhiannon. 'That goes for you too, young lady.'

'Well thanks, dude.' She held out her hand to give him some skin and Floyd obliged her, swiping the palm of his hand across hers. 'It's most excellent to be here.'

'Floyd is the eyes and ears of our operation.' Rhun placed a hand on his colleague's shoulder. 'Anything you want to know about anyone on the planet, Floyd is the man to ask.'

This information brought a smile to Tory's face.

'Doc Alexander?'

The computer boffin clapped his hands and laughed. 'One of my favourite case studies.'

'Are you a hacker then?' Rhiannon took a seat on the old, but comfortable sofa.

'Darlin', I have designed encryption codes for the computer systems of some of the world's biggest security agencies. Hacker is such an ugly job description, I prefer to think of myself as a code breaker.'

'And there's not a code in existence that Floyd can't break,' Rhun boasted, and Floyd winked to comfirm the claim.

'You and Ray Murdoch have got to meet,' Tory told him.

'The missing ICA engineer?' Floyd stood, provoked by the possibilities this presented. 'The one who designed the monitoring systems for their new fusion reactors?'

'The very one.' Tory observed Floyd's excitement snowball.

'He hasn't destroyed his research, has he?' He gripped hold of Tory's shoulders in a sudden state of panic.

'No, not yet.'

'Hah-ha!' Floyd threw his baseball cap into the air.

'We can really mess with the big boys now!'

'Well.' Tory was pleased by Floyd's obvious enthusiasm. 'Speaking of the others, shouldn't we go get them?'

'That's probably a good idea,' Rhun considered, 'before the Navy drives them onto dry land.'

Tory freaked. 'I thought you said they were in no danger?!'

'Well, they're not if we leave now.' Rhun held out his hand, very calm about the whole affair.

No sooner had Tory touched her son, than they were gone.

Floyd gave a chuckle, looking at Rhiannon on his sofa. 'The government doesn't stand a chance.'

Back on the control deck of the Goddess, Tory and Rhun found the crew in a full state of alert. Three fully-armed navy submersibles were closing in on them from the north, south and west; in ten minutes time they would be forced to surface due to shallow water.

'Shut down all your systems,' Rhun instructed Teo.

Teo glanced back, not recognising the voice. 'Who the hell are you?'

'He's my son,' Tory advised in haste. 'Do as he tells you.'

'But without power, we're stuffed!'

Rhun hoisted Teo from the pilot's seat and took control of the vessel. He placed both hands on the control panel and, seconds later - blackout.

'Jesus.' Naomi gasped, horrified - as were the rest of the crew. Plummeting downwards out of control through the inky blackness was their worst fear come true.

Suddenly, everything in the vessel, including the occupants, took on an eerie blue-white glow that became brighter and brighter. It no longer felt like they were sinking; rather, they drifted, floated, flew even.

When the illumination subsided the natural light from the subterranean cavern poured in through the portholes of their craft. Rhun had brought the Goddess to rest on the ramp he'd had built for her.

'That was incredible.' Tory kissed her son's cheek; it was obvious she had much work to do on her own psyche.

'Well, holy shit. Will you look at this?' Brian perused the world outside. 'Where the hell are we?' He smiled at Tory and his nephew, most relieved to be wherever he was.

'Welcome to Central Australia, Brockwell.' Rhun, a little drained from his feat, held out a hand to shake his uncle's.

'Brian,' Tory corrected Rhun in a whisper.

'I knew what he meant.' Brian gladly shook his nephew's hand.

Rhun raised himself from the pilot's seat, receiving a round of applause from the very appreciative crew. He cast his eyes over them, unable to believe how many of them he recognised. Bryce. He spotted Ray first who in the Dark Ages had been his closest and most trusted friend - for over sixty years. Selwyn. His eyes passed by Noah to Daniel - Cai ... and Queen Katren of Powys. Rhun's sights came to rest on Naomi in the seat beside him.