Author's Note: Yes, it's short. But the next section is really long. So that'll make up for it.

I love the idea that Seo is constructed the way that human beings would assume Gallifreyan children should be, without actually knowing how a Gallifreyan child should look or act. It's something I don't think I've ever seen, before.

One of the things I love about this is that you can see the Doctor and Buffy both doing exactly the same thing, when confronted with Seo. Namely, launching themselves deep into denial about it. And the Doctor will do something similar when confronted with Jenny, later on, who is (or, at least, I believe she is) a "properly constructed" Gallifreyan child.

(Okay, maybe not perfectly constructed, but better than Seo.)

Keep in mind, when you read this, that Seo grew up in the Axis. Which is basically a Doctor museum, or at least to a certain extent. So, sometimes, she knows all sorts of totally random tidbits about him. And, other times, she knows absolutely nothing.

Anyways. Enjoy!

The moment Buffy and Seo were far enough out of the room that Martha was sure they couldn't overhear, she snuck over to the Doctor. And asked the question that was most on her mind.

"So… this is what the Face of Boe meant, right?" she asked. "When he said you weren't alone?"

The Doctor froze. His face losing all traces of happiness. His eyes fixed on the machine ahead of him. "No," he said, at last.

Then got back to work, yanking things out of the machine and rearranging them, jumping about and making a mess of what was already pretty messy to begin with.

"Why not?" Martha demanded. "You said it had to be another Time Lord, and Seo—"

"Isn't one," the Doctor replied. He put his foot up on the edge, bracing himself as he yanked at a long red cable.

Martha folded her arms. "Don't tell me you're one of those people who believes in 'pure blood'."

The Doctor looked up at Martha. "Martha, Seo isn't a Time Lord; she's a biological construct created to partially resemble my personality and physiology," he said. The cable snapped off in his hands, and he began running it around the base of the machine. "And her creators couldn't even get that right."

"She seems to act a lot like you," Martha replied.

"Genetically, she's a hodge-podge," the Doctor said, buzzing at a section of the machine with his sonic. "A shambles. Most of the necessary physiological elements are there, yes, but they're all a bit wrong. Off. Mixed up. As if whoever put her together hadn't the slightest notion what they were doing." He reconnected two wires, causing the machine to spark in front of him. "She's not a Time Lord. Not even a Gallifreyan. More like… a botched science experiment." He shook out his fingers. "A dangerous botched science experiment."

"Flattering," said Martha.

"I'm sorry, but that's what she is," said the Doctor, jumping to his feet. "If you don't believe me, try taking a photo of her on your mobile."

Martha remembered what Buffy had told her. "She doesn't show up in photos," said Martha. She frowned. "Isn't even able to see herself in the mirror." She puzzled that over. Then looked at the Doctor. "How does that one work?"

"Her optical receptors are tuned to see a different dimensional frequency than the rest of her," the Doctor replied. "Told you. Hodge-podge." He grabbed one of the speakers, and jerked it off the top, tossing it aside. "It's a wonder she's even alive and breathing to begin with. I can see bits of my other incarnations popping to the surface of her personality — and that's not supposed to happen in Gallifreyan children. Not at all." Muttering under his breath, "I'm surprised she can regenerate."

"And what is this 'regeneration' you all keep talking about?" Martha asked.

The Doctor launched into a whirlwind explanation, as he reconfigured the machine. One Martha could barely keep up with, but managed to understand the gist of.

"None of which explains any of the so-called 'silver stuff' produced when Seo tapped into it," the Doctor concluded. "That's certainly not supposed to happen."

"So you think the reason the Powers that Be think she's so dangerous is because of her… genetic anomalies?" Martha asked. Amending her phrasing to be less insulting as she noticed Seo and Buffy re-entering the room.

"No idea," the Doctor said. "Biological construct like Seo? Hodge-podge. Dangerous botched science experiment. Like I said. Hard to tell what's what, when you're built as shakily… as…" He noticed who'd just entered the room, and scratched the back of his neck. "Rude. Right. Have to stop being rude."

The Doctor's actual daughter or not, it appeared that Seo had inherited the Doctor's sense of 'plastering on emotions she didn't actually feel'. Because while she'd obviously been crying a few seconds earlier, she now planted a perky grin on her face, and pretended she was completely fine.

"She's spent the last two months calling me a shape-shifting, planet-brainwashing demon," Seo offered, gesturing at Buffy.

Buffy's face turned red.

Martha looked between the Doctor and Buffy, both of whom were looking incredibly awkward. "I can't believe you two!" she said.

"Okay, in my defense," said Buffy, "do you know how weird it is having your time traveling Time Lord daughter show up on your doorstep?"

"She's not a Time…" the Doctor started, then seemed to realize he was just digging his foot in, deeper. "Oh, never mind." He went back to rearranging Seo's machine.

"What are you doing?" Seo asked, stepping around to try to peer at his jiggery-pokery.

"Altering your machine," said the Doctor, "to make sure it always does what it accidentally did to Martha. Transport us inter-dimensionally. And back, of course."

"Couldn't we just take the TARDIS?" Buffy asked.

The Doctor's eyes rested on Seo. For a few seconds he said nothing. A hint of suspicion in his corneas. Then grinned back at the rest of them. "Nah, TARDIS can stay here."

If Seo noticed anything, she didn't mention it. Just continued to examine what the Doctor was doing with curious eyes. She reached into her pocket, as if musing something over. Then her eyes lit up, and she beamed.

"Would you like—?" she began, taking something out.

"The answer to your next question is no," the Doctor cut in, ducking behind the machine. "I would not like a Jelly Baby."

Seo frowned in confusion, mouthing the words, 'Jelly Baby?'

"Not like you to turn down sweets," Martha remarked to the Doctor.

The Doctor glanced up at her, as if recalling she was there. "Martha doesn't want a Jelly Baby, either," he said, turning back to his work.

"Oh," said Seo. "Well, can I give her a kiss?"

The Doctor started so violently, he hit his head against the lip of the machine. "What?!"

He looked up, to discover Seo with her hand out, a bunch of Hershey's Kisses in her palm. A completely innocent look plastered across her face, as if she had no idea why the Doctor would possibly find that odd.

Martha cracked up.

"Oh, yes, that's right," said Seo, closing her hand, thinking it over, carefully. "I forgot. Real Time Lords don't call them 'kisses'. You call them 'genetic transfers'."

The Doctor almost hit his head, again.

"What…?! But…?! You…?!" he exclaimed. "How…?!"

"What?" asked Seo, with wide, innocent eyes, as if she had absolutely no idea of the significance of what she just said. "Did I say something wrong?" She then turned to Buffy, and offered her the handful of chocolates. "Do you want a genetic transfer?"

Martha, by this point, was laughing so hard, she could barely breathe.

Buffy took three chocolates, then tossed one to Martha, and one to the Doctor. "I've learned over the last two months," she told them. "Don't get into verbal sparring matches with Seo. She always wins."