The TARDIS had definitely NOT materialised where it should have done. They knew that from the viewscreen that showed them to be in what seemed to be a hall of mirrors.

"Ok," The Doctor said. "I admit it, we're off course. And I haven't a clue where we are. Shall we go take a look, anyway?"

"Might as well," Rose said. She wasn't too worried. They were not in a huge hurry to be anywhere. He reached out his hand to her and they stepped out of the TARDIS together.

He turned to secure the TARDIS door and she took a few more steps forward. He looked up to speak to her and she was gone. He stepped forward calling her name softly and when he looked around the TARDIS had disappeared.

"Oh no," he groaned. "One of THOSE bloody places."

Rose was starting to feel scared. She had no idea where she was or where the Doctor was. She was in a maze of mirrors, some of which must be deceptive, or maybe they moved somehow, because when she turned back the way she came she couldn't find where that was.

She must have been walking for an hour or more, feeling more and more worried that there was no end to the maze and that she would NEVER find either The Doctor or the TARDIS when she thought she heard footsteps. She stopped. The steps continued. It was SOMEBODY at least. And she prayed it was somebody with only two arms and two legs and no desire to eat her.

She was relieved when she saw it WAS just an ordinary looking man, though she wondered how many more people were in the maze and WHERE WAS The Doctor?

"Hello, are you lost too?" The man who spoke to her was in his fifties, a kind looking face under a white felt hat and an odd assortment of clothes including a v-necked jersey with a pattern of red question marks and an umbrella with a handle that also looked like a question mark.

"Yes," Rose said. "What is this place?"

"I have no idea," he said. "Who are you?"

"I'm Rose," Rose answered automatically. "Who are you?"

"I'm The Doctor."

"No, you're not. No, you can't be. MY Doctor is somewhere here. I just can't find him."

"Ah," he said. "We've got a time paradox as WELL as whatever else is going on." He looked at her closely. "I don't know you. So you must be from the future. What number is your Doctor?"

"Number?"

"Of regenerations."

"Oh… ninth…" Rose told him.

"Ah. I'm the seventh."

"You're older than he is," she said.

"No, I just look older." He took her arm and they walked on along the strange glass corridor as they talked. "He must be older than me. I was 900 last birthday. What about YOUR Doctor?"

"950. I bought him a new jumper. Not as snazzy as yours. He tends to go for plain colours."

"Only fifty years and TWO regenerations?" The SEVENTH Doctor, as Rose supposed she ought to think of him, looked worried. "Doesn't give ME much time, does it? And what happened to the one inbetween?"

"I don't know. He doesn't want to talk about it much. But I suppose it was the Time War."

"Time War?" He really DID look worried then. Rose stopped and looked at him.

"You're real, aren't you? You're not one of the ghosts from SangC'lune. Because if you were you'd share his memories and know all about that."

"You KNOW about SangC'lune?" The Seventh Doctor looked at her curiously. "I've never even been there myself."

"WE go there all the time. It's one of our SPECIAL places." It was then, as she said that, that he looked at her fully and his eye was drawn to her pendant. He reached and touched it tenderly and his eyes looked as HER Doctor's did sometimes - very soft and far-away.

"I…. gave that to you?" The "I" struck her as odd at first, but of course he WAS the same man. He WAS The Doctor.

"Yes… he… you… did," Rose answered

"We're THAT close?"

"Yes, we are."

"I shouldn't know this," he said. "I shouldn't know about the Time War either. Whatever that is, I need to find out myself in the fullness of time. But… number nine is a lucky man. I hope he realises that. We've been too long without that sort of love."

"I shouldn't have said that stuff."

"Not your fault. You didn't ask to be stuck here with me. Come on. Let's go find your Doctor and my Ace."

"Ace? She's here? She's YOUR companion?"

"You know Ace?"

"Yeah. She's been around a couple of times. We fought vampyres in Ireland and big space bugs in the outer solar system."

"Sounds like you've been around a couple of times, too. The things I've dragged innocent young girls into. I ought to be ashamed of myself."

"Wouldn't miss it for the world," Rose assured him. "Do you think Ace is with MY Doctor?"

"That's a possibility," The Doctor said. "Only one way to find out."

The Ninth Doctor was worried about Rose. He knew she must be in the maze somewhere. But what else was in it? And what WAS it all about?

"Rose…" He yelled as he caught a glimpse of a figure turning into the next corridor. He ran after her. Only when he reached her and spun her around did he realise it was not Rose. It was….

"ACE?" He looked at her in astonishment. This was not the woman he had met up with again twice in the past couple of years, but the sixteen year old of his past, and he quickly realised that there was a paradox running here.

"I don't know you?" she said suspiciously. "How do you know my name?" She looked him up and down quickly, impressed by the man in black look, especially the battered leather jacket. It went with his face - good looking but definitely lived in.

"Ace… I know you." He smiled. "You're my favourite juvenile delinquent… and you never did stop calling me professor."

"DOCTOR?" Ace looked at him in astonishment. "No…it can't be."

"It is. But don't worry. We're mixed up in some kind of paradox, that's all."

"That's ALL? Typical of you! You never take danger seriously."

"That's my Ace," he said hugging her. "It's serious. And I have to find my Rose…"

"Rose?"

"She's…. She's mine now… You moved on…"

"Don't tell me anything. The Doctor says we shouldn't know too much about our own future."

"Yes, I do say that," he said and flashed her a smile that she responded to in kind.

"I wonder if your Rose is with MY Doctor."

"That's a possibility. We'd better try to find out. Come on, Ace. No point hanging around here chin-wagging."

"Coming, professor," she said, slinging her holdall over her shoulder. He looked at her again and smiled. He WAS desperately worried about Rose. It was an ache inside him. But if she was with the incarnation of himself that had been Ace's Doctor then she was fine. Come to think of it, if she was with any of his incarnations they would take care of her. But number seven was especially avuncular in his relationships with the young women who tagged along. He WOULD look after her.

"What happens when you meet up with my Doctor?" Ace asked as they walked along.

"What happens if the two of you come together?" Rose asked The Seventh Doctor.

"I don't know," The Ninth Doctor replied.

"I think we'll find out when it happens," The Seventh Doctor said.

"I hate bloody paradoxes," The Ninth Doctor said.

"Paradoxes…. They're such a nuisance," The Seventh Doctor muttered as they kept walking.

"Who is that?" Ace said seeing another figure somewhere up ahead. A young girl. As they walked towards her, they could hear her crying softly as she walked through the endless glass corridors.

"Well, it's not Rose," The Doctor said. He looked again and his face paled and he groaned out loud. "Oh, how many of us are stuck in this place?" Then he called the girl by name and ran towards her. Ace caught up with him just as he picked her up in his arms and hugged her tightly.

"Hush, Julia," he said. "It's all right. I'm here with you. I'll never let you be hurt."

"Professor?" Ace kept on looking as he set the girl on her feet. She had stopped crying now and was just very puzzled.

"Chrístõ?" She looked at The Ninth Doctor, taking in his clothes, especially the leather jacket, and though she was thirteen years old and still had a lot to learn she understood that anything was possible in his world - his universe - and recognising that this much older man WAS her Chrístõ in some way was easy.

"Yes, Julia," he said, and he blinked back tears to be strong for her, and for Ace, who, beneath her feistiness, had a lot of lost little girl about her, too. "But YOUR Chrístõ must be here somewhere, too. We'll find him together."

Rose and the Seventh Doctor had found him. As he ran down the corridor towards them The Doctor gave a soft gasp of recognition of himself as a young student Time Lord. He looked at Rose and reached and tucked her pendant into the top of her t-shirt. "For the moment, I think it's best HE doesn't see that. He hasn't even married his first wife yet. He doesn't need to know she's dead and buried and he's got a second wife now."

"We're not… I'm not his…" Rose began, but she left the sentence unfinished as the young man she jokingly called Drop Dead Gorgeous the last time a paradox had crossed their paths stopped a few feet from them. She had only seen him on a viewscreen the last time. This time, close up, she decided her epithet was right.

"Chrístõ…" she said. "Are you ok?"

"How do you know my name?" he asked, puzzled.

"I've seen you before," Rose explained. "But you didn't see me. Once on a spaceship. I was in the TARDIS and The Doctor talked to you through a hologram. And once… maybe it hasn't happened yet… in Rome…"

"The Trevi Plaza?" He said, remembering. "World Cup year…"

"Yes. That was… the woman you helped… was my mum."

"And The Doctor… the guy with the grotty leather jacket… that was me in the future…"

"YES." Rose laughed and eyed his smart new jacket. "And by the way, he was right. It IS the SAME jacket, so you might want to rethink the 'grotty' comment. And seeing as THIS guy is ALSO you, and YOU chose THAT jumper, I'd lay off fashion comments altogether."

"We're in some kind of temporal anomaly," the Seventh Doctor explained to his younger self. "As far as we can guess there are three of us now…. and those who were with us. Were you… Who were you travelling with?"

"Julia," he said. "She's only thirteen. She came for a trip with me in the spring holiday. She'll be so scared on her own."

"She might not be on her own," Rose said, wanting to comfort him. "I found him. And we found you. And MY Doctor and Ace are in here somewhere as well. Don't worry." She put a hand on his shoulder. It was an instinctive thing, but how strange it was. The leather jacket FELT the same even if it looked different before the centuries of misuse. If she had closed her eyes at that moment, it would have felt like HIM. And of course it WAS. This 'teenager' - though she guessed he was probably about 200 years old, being a Time Lord after all - WAS her Doctor, and so was the nice 50-something with the crazy jumper. They were BOTH the man she loved, and it was a small comfort even though her heart ached for the REAL him. "Come on, we'd better keep moving."

"I'm not so sure about that," The Seventh Doctor said. "I think the best thing we could do is stay put and wait for everyone else to catch us up. After all, the three of us found each other. And frankly, these 900 year old bones would rather not go running around too much. It's all right for you youngsters."

"My 950 year old Doctor runs plenty. And he does five kinds of martial arts," Rose said.

"Well, good for him. I prefer a nice cup of tea, a good book and my favourite armchair."

Fit though he might be, the Ninth Doctor's party had stopped for a rest after walking what seemed miles of empty glass corridor. Julia, tired not just from walking but from the emotional stress, was sleeping with her head leaning against The Doctor's shoulder. He adjusted his position and closed his arm protectively around her.

"So, who is Julia?" Ace asked. "And how does she fit into things?"

"She is my wife."

"Come again?" Ace looked at him with an understandably puzzled expression.

"When she was eleven, the much younger me that SHE is looking for rescued her from a bunch of space vampyres that had killed her parents. I read her future timeline and I knew I was going to marry her. I took her to stay with her aunt and uncle and told them I was going to be a part of her life. And I paid for her to go to a good school and bought her presents, and took her on holidays to exotic planets until she was old enough for me to be formally engaged to her. This seems to have happened during one of the times we were travelling together."

"I never even knew you'd been married, professor."

"By the time I knew you, Ace, Julia was just a sweet memory of the brightest parts of a long, dark life."

"I understand," Ace told him. The look in his eyes told her all she needed to know. No wonder he'd never told her.

"If this happened in your past, then do you remember this happening?" Ace asked. "Do you know how it will end?"

"No, I don't," he said and frowned. "I should, shouldn't I? That's the REAL paradox. I should remember it TWICE, because it happened when I was the seventh incarnation with YOU as well. Some things I might have forgotten from when I was a teenager, but it was only fifty odd years since WE were knocking about together."

"Fifty years? But…"

"I live outside your time, Ace."

"I don't understand."

"Don't try to. Does your head in. Does mine, sometimes. It's been a long, hard fifty years. There's stuff happened in that time that even gives me nightmares. And if it wasn't for Rose I'd be happy to turn back the clock to the innocent times when you and I were together."

Ace looked at him. She wondered what had happened to him since they were together. He did seem very much more serious than her Doctor had been, as if he had suffered too many hurts and disappointments. She touched his arm and smiled reassuringly at him. He smiled back and whispered, almost too quietly for her to hear, "Thank you."

"This was just after the trip to Rimos 9 - the planet with all the breathtaking waterfalls?" The Seventh Doctor asked his younger self. "The year she was thirteen?"

"Yes," Chrístõ said. "We've been there for three weeks. We're on our way back to Beta Delta IV. School starts on Monday."

"I remember that as a completely uneventful trip," The Seventh Doctor said. "THIS is all wrong."

"I hate time paradoxes," The Ninth Doctor said to Ace. "They mess with my head." He touched the silver pendant that Julia wore around her neck. He remembered the only time she took it off was for gymnastics and ballet. Her teachers had been uppity about it and he'd gone down to the school and given them his full on Time Lord Autocrat mode and made them change their rules. He could be VERY arrogant when it suited him. He looked at the pendant again and at Julia as she slept. His hearts were both torn. He was, against all probability, holding in his arms a girl who would grow up to be his wife, whom he never stopped loving, whose memory had been an ache deep within him for centuries. And at the same time he was worried sick about Rose, the woman he loved now - if this WAS now. He wasn't entirely sure this WAS any time or place. That might explain the lack of memories of this event.

Rose was asleep, too. And it was Chrístõ she leaned against as she slept. Though she was a stranger to him, he gently put his arm about her, comforting her in the strange time they were all seeing each other through. As he did, his hand caught the silver chain about her neck and the pendant pulled from inside her t-shirt. He recognised it at once. He looked at his older self sitting nearby.

"That's Julia's," he said hoarsely. "Why has she…"

"Chrístõ…" The Seventh Doctor shook his head and frowned. "Good heavens, is that REALLY my name? I had forgotten. Before it was Julia's, it was our mother's. Father gave it to her as a betrothal present. You gave it to Julia as a promise that you would be together in the future." The Seventh Doctor thought about where it went next. Long after Julia was dead and buried he had given it to his son as a wedding gift to his bride. After THEY were dead and he painfully sorted through their effects the pendant was the only thing he wanted to keep in remembrance. He couldn't tell the young version of himself how much heartbreak there was in his future. But he had to have realised that he was a Time Lord with a long lifespan and Julia was a fragile human. He looked at his face and he could see he HAD worked it out.

"Oh," he said very simply and rather sadly as he looked at Rose.

"This girl is nothing to do with you," The Seventh Doctor said. "She's nothing to do with me, either, in that sense. In the future another version of us loves her as much as I loved Julia - as much as you WILL love her. All that matters to YOU is that you and Julia have a wonderful, happy life together. And you KNOW that because you read her future so there's no harm in telling you that. Beyond that life, don't even try to think right now. It'll drive you mad." And he reached out, almost without thinking, and touched his younger self on the arm reassuringly. It was a dumb thing to do and he cursed his stupidity, but the fatal cataclysm he had expected didn't happen. Rather, he felt a tingle as of static electricity and suddenly his telepathic circuits seemed to be in overdrive. Rose woke as Chrístõ jerked upright from the lounging position he was in and was startled by the wide-eyed and surprised expression on the faces of both men.

"I can feel you," Chrístõ said. "And… I can feel the other one, too."

"So can I," the Seventh Doctor said. "Focus, let him know where we are."

"WOW!" The Ninth Doctor closed his eyes as he felt the telepathic shock and saw, through four eyes at once, from two different angles, his Rose. His heart leapt. As strange as the vision was, he knew it was real. And he at least knew where she was.

"Come on," he said to Ace, waking Julia as gently as he could and telling her they were moving again. They walked quickly, he holding both their hands.

"There…" Ace said as they turned a corner. Ahead, he could SEE Rose, and Ace's Doctor in that ridiculous jumper, and young Chrístõ, the only one of his past lives with dress sense.

But there was no way through to them. A solid wall of glass separated them. Frustrated he threw himself against it and got a badly bruised shoulder for his pains. He was aware of his other two incarnations in his head emotionally, but he couldn't connect verbally. He saw their shocked expressions at what he had tried to do. Ace put it into words.

"Are you nuts? If that HAD worked you'd have been ripped to shreds by broken glass and some of us with you."

"Sorry," he said with a grimace. But Chrístõ had clearly had an idea. He moved close to the glass and blew on it, slowly and insistently, and with breath that must have been freezing as it left an icy patch of frozen vapour on the glass. Then before it melted he wrote, backwards with his finger, 'snc scrwdrvr." The Ninth Doctor grinned as he understood and pulled that instrument from his jacket pocket and the same moment Chrístõ reached into the same pocket for his. 700 years between them and 8 lives, and they were SO alike, he thought. The Seventh Doctor reached for his as well and like the Three Musketeers pledging 'All for one' they all touched the same spot on the glass at once and began etching a groove in it from both sides. They slowly cut a space big enough to step through. Chrístõ and the Seventh Doctor took the weight of it and moved it aside and The Ninth Doctor, Ace and Julia stepped through.

Rose flung herself on her Doctor. Julia ran to Chrístõ and literally leapt into his arms, her legs around his waist and her arms around his neck. He smiled as he held her that way and watched his older self with the woman who was his much later destiny. Ace and HER Doctor hugged in a more platonic and restrained way but both smiled to see the first and latest incarnations so happy to be reunited. Standing, as it were, in the gap between them, was nearly as emotional.

"What now?" Ace asked as the emotions settled down and they all turned to look at each other. "There must be THREE TARDISes here somewhere. Does ANYONE know where they parked?"

"Nope," The Ninth Doctor said. "We've walked for hours."

"I'm not even sure what mine decided to look like today," Chrístõ said. "Almost the moment we stepped out we seemed to be separated and I was nowhere near it."

"I forgot…. Your Chameleon circuit still worked," the Seventh Doctor said to him.

"At least we'll know which one IS yours. We've got two police boxes."

"Least of the problems," Rose said. "How DO we get out of the maze?"

The Ninth Doctor was looking at his sonic screwdriver. He walked over to Chrístõ and took his from him and looked at it as well, and his seventh incarnation. He put them together and switched all three on. Nothing happened. He looked disappointed.

"What were you trying to do?" Ace asked him.

"Break the paradox by bringing together things that are the identical object."

"Er… they're NOT identical," The Seventh Doctor said taking his screwdriver back and passing the third to his younger self. "Chrístõ's one broke down when we were back on Gallifrey. If I recall he broke it using it to put up SHELVES. It was NEVER any good as a screwdriver. He bought a new one. And THAT looks like an upgrade as well. They're different tools."

"Ah," The Ninth Doctor said. "There must be something that's identical."

"Well, YOU all are, aren't you?" Rose said.

"Not quite," the Seventh Doctor said. "Our eyes are different." He looked at Chrístõ. "His are brown, mine are blue and his…." He looked closely at his ninth incarnation. "Oh, they look so much like our mother's… His are grey."

"That slight difference means that our DNA is that LITTLE tiny bit different," The Ninth Doctor explained. "We're about as close genetically as brothers, maybe. But not exact copies of the same person. Just as well, seeing as we're all standing here."

"I suspect we'd be in trouble if we were anywhere real," The Seventh Doctor said. "But this place is something else."

"Ok, so is there anything that is identical here," Rose asked. "Something that connects in some way and would bust the paradox or whatever you're thinking it will do?"

Chrístõ looked at Rose, then he looked at Julia, by his side holding his hand.

"Of course there is," he said. "And I'm surprised you two didn't spot it. Do I get thick when I'm older or something?"

"What?" The Ninth Doctor asked looking at him. The Seventh Doctor was equally puzzled.

"I think you DID get thick," Rose said, catching on. "Julia, come here…" She reached out her hand to the young girl, who left Chrístõ's side and came and put her hand in hers. Realisation dawned.

"The Alpha and the Omega," the Seventh Doctor said.

"The first and the last." The Ninth Doctor added. "Of course." He looked at Rose and Julia standing together and he gently turned them to face each other. "You three come closer," he told his other two selves and Ace. "We're surrounded by glass and I don't know what this will do. But let's be as small a target as possible." They all gathered in a tight huddle as he took hold of the pendants the two girls were wearing and pressed them together. They glowed as if white hot, but nothing worse happened. Around them, though, they heard the glass shatter. It did so in such a way that it simply collapsed down into millions of tiny fragments and they were in no danger. But the noise was unbelievable.

And the silence that came after was nearly as startling. They looked about them at the miles of broken glass and at three objects still standing, not more than a few yards from where they were. Two of them were identical blue police public call boxes. The other was roughly the same size, but seemed to be a hexagon of crystal mirrors. Each of them had etched in the centre of them two Greek letters - .

"Theta Sigma," The Ninth Doctor said, smiling as he saw it. "Seems a long time since I was called that." Chrístõ looked at him and his other counterpart as he stepped up to the door, Julia's hand clutched in his tightly. He made as if to reach out to him but the Ninth Doctor stepped back. "Better not. This isn't in the paradox any more. I'm not sure it's normality either, but we ought to avoid physical contact just in case."

"See you next time the universe throws a wobbly then," Chrístõ said and stepped into his TARDIS. A moment later it dematerialised. The Ninth Doctor felt a little sad. He liked his teenage self. It would be nice to spend more time talking to him. He turned to his other incarnation. He wasn't so bad either, really. He'd looked after Rose for him, and he was grateful for that.

"Well do YOU know which one is which of these?" he asked.

"No. We'll just have to find out. And they both turned and unlocked the doors of the two TARDIS's. Ace and Rose watched as they both looked inside and then swapped. "What on EARTH did you DO to the interior of YOURS?" the Seventh Doctor asked. "Come along Ace."

"Coming Professor," she said. And they, too, were gone. The Ninth Doctor looked at Rose and held out his hand to her. She came at once.

"I don't care what it looks like," she said as they stepped into the TARDIS. It's still OUR TARDIS. Our HOME."