For a moment Xan stood frozen, and then she whispered, "You mean it?" with so much emotion that many people would want to back away before answering, in case they'll be hit by shrapnel of happiness.

He took her hand with a smile and gently pulled it forward, guiding it towards the left side of his chest. Xan swallowed as she felt, through the fabric, the unmistakable pulse of a heart beating. She moved her hand to the right side. The same. Perfect symmetry,she thought. There's one place where humans lack it physiologically. Two lungs, two eyes, two arms, legs, kidneys, ears, brain hemispheres. But only one...

"Oh. My god. Oh my god. You're... you... all this time... I didn't know," she whispered, as if afraid she had committed an inexcusable social crime. "I hoped... just that, though, nothing more... that maybe..." Then she pulled herself together and sat, her fingers making a steeple over her chin. The Doctor lay back and stared at the sky.

"So what are you, if not human?"

"Something called a Time Lord."

Xan shivered all of a sudden. She gazed at the plain that stretched out over the world. The world... right now those words meant very little. Thoughts gathered slowly.

"What does that mean? What does it mean, to say that I am human and you are not?" She sifted sand through her fingers. "Who are you?"

"It's a long story."

"I like stories," Xan said. "And we've got all the time in the universe."

The Doctor sat, legs crossed, and clasped his hands together. "Well," he said finally, pulling his knees up and watching the stars, "It's not like the usual story. It's hard to put together... because... there is no beginning."

The astral wind blew the sand into sparkling waves that twinkled down gently.

"There is no beginning. Just get that, right from the start, 'cause that's what you need to start with. Start in the middle, because that's all there is..."

Xan listened as he spoke.

"So there is no end. No beginning. Right? Wrong. I'd know. I've seen it. Every second of it. That's who I am.

"...You know... you know how when you dream, you know exactly what's going to happen...?"

She nodded. It was the one place where time meant nothing. Is that what it means to see all of time? Is the whole world like a dream to him? When she met his gaze for a moment, she saw once more the impossible reflections smoldering in his eyes, and knew now that they were real.

"...That's me. Every day, every hour... It's night, and you're staring up at the sky..." he pointed up. "...you see a flash of fire..." as a blaze of light burned brightly in the heavens. "What happen if you wish that star never fell?

"I happen. That's what. 'Cos that's who I am."

Then he laughed. "Actually it was. Literally. That was me, right there. That falling thing you saw. And so now, here I am."

"Here you are," she echoed. Then she thought for a moment and asked, "If you're from another planet, somewhere way off in the other side of the universe, then how come you look like a human?"

"Why do you look like a Time Lord?"

"And why are those two questions nearly identical?" retorted Xan, who didn't let people dodge her questions, even if they were aliens.

This answer befuddled the Doctor. You didn't expect something like that as a response. Usually being cryptic made people feel inferior, so they let up. "Convergent evolution," he said coolly.

"Don't pull that on me," said Xan Russell, paleogeneticist. "Do a bird's wings look anything like a butterfly's wings?"

"You don't realize how successful bipedalism is..."

"But everything looks the same. Relative proportions of body parts. Bone and muscle arrangement." But when she looked again, she saw that there was something slightly different about the way his cheekbones curved below his eyes... or was it the way the creases on his palms didn't really match what you'd expect... or the texture of his skin...? The pattern of veins on his wrists? The shape of his shoulder blades? The way he moved, which was just a little more fluid that normal? His smell, even? Tiny, almost imperceptible changes. Good ones, mostly. Enough to make him attractive, handsome. Now Xan realized why. Humans, since they often look alike, are very keenly aware of, in particular, facial structure. The Doctor looked human enough to pass off as one, but people did notice he was different. They just misinterpreted it. The resemblance was too strong to be the result of random evolution, though. "Homologous structures," Xan said uncertainly.

"Analogous," he insisted.

"But just because you have a few different organs doesn't make you a different species! Some people have an appendix. Some don't. Some have mammary glands. Some don't! Pretty big differences."

"Yeah, but that's not all..."

"There'd be some pretty big anatomical differences between me and you even if you were human. That is... you are male, right?"

"Do I look like a girl?" demanded the Doctor, offended.

"Do you have to? You're not human. How should I know what the egg-bearing gender looks like? Unless you bud or something, like a medusa."

"I don't! Well... not usually, anyway!"

"Not... usually?"

"It was only once! And it's entirely unique! A statistical anomaly. Yes, I am male, thank you for asking!"

"So now suppose that... I don't know... let's say we both go entirely insane and end up married..."

"What?"

"Hypothetically."

"Why are we getting married all of a sudden?"

"It's hypothetical. But say that happened and..."

"No offence, but..."

"It's biology," pleaded Xan. "I'm talking about the definition of a species. Biology."

"Oh, good. For a second there I thought you were talking about matrimony..."

"That was a euphemism," she snapped. "I was talking about offspring."

The Doctor looked scandalized. "I hardly know you!"

"It's a thought experiment!" Xan wailed, as she began to realize this was a lost cause. "You can do whatever you like in a thought experiment!"

"I don't really want to know what you think about, then."

"Look, if Einstein imagined riding a beam of light-"

"Yeah, but he didn't mean it that way..."

"Someone else, then!" Xan bawled, at the end of her tether. "Go marry someone else! Not me! Please don't! Anyone else! Just not me! Anyone but me!"

A pause. "Well... that isn't very nice." He looked hurt.

"The definition of a species is a group of individuals in which all possible mating pairs can produce fertile offspring," said Xan stiffly. "That was what I was getting at. If a Time Lord and a human can produce fertile offspring, then they are members of the same species, regardless of evolutionary differences."

"That's all?"

"Yes."

"Oh." He said it with theatric disappointment. "Right. Yes. Of course."

"You," said Xan, with great dignity, "are a buffoon."

The Doctor rubbed an ear contemplatively. "No one's ever called me that," he said finally, "And I've been to the seventeenth century."

"More fool them, then." She lay down on her makeshift pillow and gave him the Evil Eye. Then she turned on her side, facing away from him.

After a little while, she rolled over onto her back. The Doctor gave her a patient grin. With a huff, she went back to lying on her side.

Minutes passed. "Aren't you tired?" Xan demanded, still on her side.

"I don't need to sleep."

"No wonder you're so weird." It was a childish thing to say, but she didn't care.

"My sleeve of care is very raveled, yes."

Xan acknowledged this by not making a snide comeback, which was high praise.

"I'm sorry if I hurt you," the Doctor said innocently. "We can still just be friends."

Xan rolled over. "I will kill you," she vowed. "Right. Now."

"Domestic abuse!" crowed the Doctor.

"First I'll throw sand in your eyes," she said murderously. "Then I'll blow your ear out with your sonic screwdriver. Then I'll..."

"What a shame. Such a great loss. Well, I must die, then so be it." He spread his arms in a gesture of self-sacrifice.

Xan hauled off and punched him in the stomach. It was a friendly punch, in that it didn't break any ribs, and might not even leave a bruise.

"Ow," he squeaked, doubling over to protect his abdomen. "Whydidyoudothat?"

It looked a lot less like pain and a lot more like mirth to Xan. She poked him in the stomach again, experimentally, before he could stop her. The Doctor shied back, trying to control the spasms of laughter. "Don'tdothat," he gasped, eyes wide. He seemed as surprised as she was by his reaction.

Oh god, Xan thought. He's ticklish.

She thought that this merited some time alone, to think things over. Xan picked up her jacket and wandered off while the Doctor got a grip on himself, finding another soft area to lie down on. The sky still turned, and she watched it with interest. Stars fell around her, lulling her to sleep. She fought it at first, but the inexorable turn of the planet put a constant pressure on her mind to relax.

In a short while, she heard footsteps, and then the Doctor lay down beside her with a thump.

"Hi," he said. Xan looked up at the sky and tried not to laugh. Just like a puppy, she thought. "Nice night, huh?"

"It's beautiful."

"It gets better. In about a half an hour, a big ol' cloud of radiation hits the ionosphere. All the particles get all churned up by the magnetic field, burn up in the atmosphere. Just wait."

"An aurora," she translated. "How do you know this?"

"I've seen it before," he said calmly. "About ten miles from here over that way. And seven miles that way. And oh, maybe a couple of miles up that way."

"It's that good? That you would see it three times?"

"Now it's four. Or more, depending on what I decide to do in the future."

"So if I go up that way and walk for a couple of miles, I'd meet you?"

"Yep."

"Isn't that a little dangerous? Wouldn't that mess up the space-time continuum?"

"It would have," he said, "if you had done it. But you didn't. I'd have remembered if you did."

She stood up. "I'm going to do it."

"Gods help us all," murmured the Doctor. "Tell me I said hi, will you?"

She took a few steps. "Here I go."

"See you in a few hundred years before now."

"A few hundred?"

"I'm nine hundred and five," said the Doctor casually. "Years. Earth years."

Xan sat back down. "Wow. That's... old."

"For a human."

"It's like... Yoda old," she mused.

"Just about, yeah."

"And not always with the same face, hmm?"

The Doctor stared. "You weren't supposed to remember that!" How did she... it didn't even... it works on everybody, no matter how special their brain! Even Donna...

"No?"

"I... er... ah... nothing."

"Oh, don't worry. The memory was certainly... pushed back a little. I mean, you have psychic paper. It wasn't so much of a stretch to imagine something more... direct. But don't try anything like that again, please."

"Well, it doesn't seem like it would work, anyway! I should have known, though. I still can't feel anything in these fingers!" He held them up.

"Not my fault."

"Yes your fault," he said indignantly. "What did you do to my hand?"

"I really don't know. You said some people had an immunity to psychic deception."

"Yes. But only to a certain degree. There's only so much strength a human mind can have."

"Maybe you're just out of practice."

He shrugged.

"You can change... who you are, what you look like... so that you live for hundreds of years... centuries..."

The Doctor was silent at first, then he nodded. "Regeneration. Cellular reconstruction. There's a price, though. You don't come out... the same. Something dies, something lives on." He picked up a glassy stone and studied it. "I wasn't born looking like this," he said. "I've had many faces before. Nine, actually."

"A hundred years for each, then?"

"Oh, we live longer than humans anyway. Age slower. I had only a few years for some, and centuries for others... a Time Lord my age usually wouldn't have gone through as many lives as I have, to tell you the truth."

"How long like this? The way you are now?"

"Five years. And... that should have been it. Remember when you found me? How I was covered in radiation, and all that? I was going to... die. Part of me. This me should be dead. I regenerated... but I didn't. Something stopped it before I could change."

"You'd been killed?"

"I almost made it. It wasn't even murder, which was looking pretty likely. Just something I should have foreseen, and didn't. Silly, really. But I didn't want to die! Who knows who I'd become? I like the way I am!"

"Nobody really wants to die. Most people would give anything to be able to live as long as you have, without fear of annihilation or... cessation of spirit."

"It's not a gift," he said slowly. "Sometimes it's more like a curse."

"Why? You have so much more time to live in."

"You wouldn't know what it's like. You wouldn't understand."

"As long as there's life, there's something to live for."

"Is that a quote?"

"No, I just made that up right now. But it sounds as if it could be true, doesn't it?"

"Maybe."

"Besides, I thought you didn't want to die."

"I don't know why I... I didn't want to lose something. Something I might never find again. I don't know what it was, but..."

Thousands of stars, twinkling in the night, and none for this wandering planet. It travels with its moons, stardust burning in the skies as it passes. Maybe it had a star, once. Perhaps it grew and grew, consuming all the inner planets of the solar system, but this one was far enough away that it escaped. Maybe the sun died one day and blew itself to dust in this nebula, and somehow the planet survived. Now it floats through the dust of its star, until a new sun forms from the ash.

Xan turned over and drew a spiral on the ground, brushed it clean, and doodled another circle. Slowly a picture began to form.

Before she finished it, she had realized what it was. And saw what it meant. "It's your language, isn't it?"

The Doctor touched the symbol. "Yes. It... was."

"Was?"

In a voice that was quite toneless, as though he had said this many times before, the Doctor told her, "There aren't any Time Lords anymore. Except for me. I'm the last one."

Dull horror made its way like a rain cloud across her thoughts as Xan began to understand what he'd said. It was the way he spoke, the way he stared at empty space, something in his eyes that grabbed hold of the tendrils of her empathy and overloaded them. She said nothing.

"A war," he answered the silence. "I suppose we lost. Or they did, the enemy. It wouldn't have made a difference. Oh, and of course they were very evil, and we were very good, and we were defending the universe from a great threat... I don't know what we thought we were doing... but we did it... and that was it. They wouldn't have shown us mercy, you see. They don't believe in mercy. Or that anything deserved to live but them."

"And you survived?"

"Yes."

"You... and no one else? How?"

"I don't know."

It might have been a lie, but Xan knew it was all she would get.

"You're sure? There couldn't be others, hiding, maybe...?" It sounded so pathetic, when she said it.

"No. I'd know if there were."

"It's a big universe..."

"Yes, but... we always find each other, in the end. There aren't any more. No one else would have survived. No one can leave the planet, Xan. Nothing can ever touch it again. There's a Time Lock, so it can't be changed. And maybe to keep the Time Lords in, too. Maybe they were as much of a threat to the universe as... as..."

He suddenly stared straight ahead, agony creasing his face. The words tumbled out before he could hold them in. "They came back," he whispered. "The Time Lords came back and tried to kill us all. Tried to end Time. Twelve years ago, for you, but I... that was what I came from. Days ago. Christmas, and the end of Time. They would have destroyed everything. I thought we were protectors. Not... monsters.

"Before it had been the enemy. Because they came back, too. The... Daleks. First it was the Emperor, and then the Cult of Skarro - that was their planet, Skarro - and then even their creator... they kept coming back, and I kept fighting...

"But then... then it wasn't the enemy at all... it was my own people... doing what the Daleks kept trying to do, and I had to stop them..."

He trailed off, and there was a sad stillness.

Xan looked down at the symbol. "It almost... almost looks like a star system, doesn't it? The phoneme here could be a planet, and this is its moon, and here would be another..." She drew another word, one of the numbers she'd learned. The Doctor watched her forefinger trace patterns on the sand. She would start with the main circle, and then from the top, clockwise. It took her less than five seconds to draw a symbol, and each one was neat and legible. That's not drawing, thought the Doctor suddenly. That's writing! She's not drawing the symbols from memory. She's writing them! And, he added sullenly, her handwriting's a lot better than mine...

Xan tried to remember the letters. How did they go... how would you write, for example, the sounds in her name?

"Star," said the Doctor, staring at the word. Xan looked up in puzzlement. "Xan means star..." He wrote two words out. Xan squinted at them.

"Your handwriting is terrible," she said.

He ignored this.

"That's my name," Xan said at last. "Or, something close to it. Xan Russell... xan uhr'sel?"

"It means... it's a phrase, means something like... someone who's been... displaced, maybe, or cut down... then you'd call them a falling star."

Xan was quiet for a while. "That's a hell of a coincidence," she muttered.

"But 'Xan' is from 'Alexandra,' right, and that's Greek..."

"Meaning, 'defender of men.' That's a good name. And 'Russell' is from 'russet,' red-haired. It's an old name. Very... European, right?"

"Right," said the Doctor in relief. "Absolutely. And Xan couldn't... stand for anything, could it?"

"Uh, no. Not unless it started with 'x-ray' or 'xenial' or 'xylophone,' or something."

"No, I don't think anyone's told me anything prophetic about xylophones lately. Just checking."

"It could stand for Xmas," pointed out Xan. "Like... Xmas At Noon! That's when something bad happens!"

"Probably you're right," admitted the Doctor, "It always is. But it doesn't have anything to do with your name."

"I know. It's a nickname, anyway."

Names... what's in a name? Everything.

"You wouldn't happen to have a...?"

"What?"

"Nothing. Never mind. Doesn't matter."

"Happen to have what?"

"Nothing." For some reason, he looked at his right hand, the one he'd said Xan had done something to. "D'you know, I lost this hand once. Well it wasn't this hand. It was another one."

What could you possibly say in response to that? "Really?"

He studied his wrist. "See, look, you can almost see where it got cut off."

"And... then what happened?"

"I grew it back."

"Ah. That's... handy."

"No, he's not here right now."

"What are you talking about?"

He gesticulated. "Budding. Medusa. Metacrisis. Don't ask."

In the corner of the sky, Xan saw a green glow. She pointed. "Is that...?"

Very slowly, the glow turned into a veil. Red laced the edges, which rippled and shone like the fiber optic curtain in the living room window of Xan's house. Bit by bit, the heavens lit up with color. Lights towered over the plain, moving in a slow dance to cover the stars in a glittering blanket.

There must be some reason why he's showing me this, Xan told herself. She allowed her mind to relax and answers drifted forward out of her subconscious. It's an incredible sight, but that's not important. It's not the beauty that's important. What is it?

Just... how many miles up, in the ionosphere? Tons of burning radioactive gas, emitting light. Gamma rays, alpha particles, beta particles, positrons. Things you really don't want to be anywhere near. They look majestic, and so... alluring, waving in the sky. But it's really something dangerous; fatal, even. Something that gets inside your bones, creeps into your cells and changes them, giving them a deadly immortality. In the sky, from far away, it's wonderful and eerie and cosmic. But don't get too close. It'll consume you, like a fire, but ever so slowly...

The sky still had patches of green glow after nearly an hour had passed. The eternal night offered no fair judge of time's passage. But now, that didn't mean anything, did it? Whatever time Xan returned to Earth, it was no longer her time. She was no longer connected to it, now drifting alone without a tether. It didn't matter how late it was anymore. How could you measure your life without the constant movement of the sun?

"Are you really nine hundred and five?" said Xan.

"Yup."

"How can you tell?" she asked craftily.

"Well... I just... I think that's right!"

"But you don't know how long a year lasts, traveling around in time. Do you have a birthday?"

"Um. I guess not."

"You don't even know how old you are."

"Yes, I do!"

"How do you know when it's been a year? And why use human years, anyway?"

"Well, I'm around nine hundred."

"Wouldn't you kind of lose track after a while?"

He sat up, struck by an unpleasant thought. "You don't think I could have turned one thousand and not noticed it? I thought I had, once, but then I thought, Nah, I'm not that old yet. Do you think that could have happened?"

"Well. Maybe." The way it was being asked sounded rhetorical.

"But that would be awful! I mean, how can you miss your thousandth birthday?"

"In Earth years?"

"Well, most of the people I know are human. Humans make a big deal about that sort of thing. I was thinking that when I turn one thousand, I could go find people I know, and maybe get presents or something, or free hugs. What if I missed it? It would have been so fun!"

"You can always just decide on an arbitrary date."

"I guess I could, but that's not really that..."

"Sportsmanlike?"

"No. But I've been telling everyone I'm nine hundred, so if they see me like this, they'll know I'm making it all up..."

One of his companions... was that what he wanted me to forget? How many people does he meet, in passing? How many people like me? Will he someday show up on my doorstep, looking like someone else, saying he's a thousand years old, yes, I checked it, can I have a free hug? Hm. Probably not.

The universe really does seem to revolve around him, doesn't it?

And time passed, stubbornly existing despite all metaphorical evidence to the contrary. The moons of this planet, this Eye of Orion, rose and fell, and one began to set. Xan had no idea how long a full rotation of this planet took, but it was shorter than on Earth. The night was as black as always.

The human mind can and will adjust itself to anything. Xan lay on her back, stargazing, wondering when this useful function would kick in. It didn't seem to be working properly. Every time she started to drift off, her eyes flew open and she stared around her, thinking, Another planet! I'm on another planet! The little jolts would wane over time, turning into simple pleasure at the idea, and then at the view, and then towards the warm air, and the low gravity, and the restful tempo of her heartbeat, and she didn't realize she was now alone. The world shifted slowly, the sands rose up into forests, the stars turned into fireflies, and the rock to blue moss. The symbols on the ground floated into the sky and turned into stars and planets, and an identity knitted itself together, binding to the memories that were fresh and new. And then the world was dropping away from her, and she fell through the sky and her skin burned away, and she landed in a metal shell which closed shut over her, while her skin stuffed itself with cotton and cogs and walked about like a living thing.