Author's Note: Welcome to the next story!

We pick up right from the end of the last one, but now... we're headed off the Toto world, and straight back to Earth!

(Can I just mention, by the way, how ingenious this particular system in Oliver is? You can really see that the Doctor is one hell of a smart guy.)

Enjoy!

Previously, in the Child of Balime…

"Where are you going next?" Seo asked, quietly.

Jenny shrugged. "Oh, here, there, anywhere really," she admitted. "Time and space to explore. Monsters to defeat. Planets to save. Running to—"

"Alone?" Seo asked. "With no family or friends or…?"

Jenny couldn't keep it back any longer. A wave of anger swept over her as she shouted, "Well, not all of us are lucky enough to have Dad follow us around looking over our shoulder!"

Seo stared.

"Sorry," Jenny said, composing herself. "Sorry, it's just…" She clenched her fists. "I haven't seen Dad since the day I was born. I… I… don't…" She looked away. "I don't have any other family."

A terrible sadness washed across Seo's face. "No family?"

Jenny didn't answer.

"No family," Seo repeated. "No home. No aunts or moms or Jacks. No one in the universe to care…"

Then she shoved a determined, stubborn look on her face. Her eyes blazing, her face certain.

And she grabbed up Jenny by the wrist.

"Nope," Seo decided. "That won't do. Not at all!"

Jenny looked up at her. "I don't…"

"If you're my sister, I can't let you race around the universe with no family and no home!" Seo told her. "I won't." She turned around, dragging Jenny after her. "So it's settled. If you don't have your own family, you'll have to borrow mine."

"I… I don't…!" Jenny tried to protest.

Alison just giggled as Seo dragged her sister inside of Oliver.

Nope. There was no use arguing with Seo when she was like this.

No use at all.

Green-Eyed Monster

"That's… ingenious," Jenny said, when she first entered the ship. Looked up, analyzing with rapt amazement. "It's beautiful. I mean, I always understood the theory of dimensional transcendentalism. But I never thought to use it on such a large scale, before. And… using it inside a space ship. That's inspired!"

Seo beamed. Bouncing up and down, looking like she was only seconds away from tugging her sister around and babbling about everything at top-Seo-speaking-speed.

Jenny turned back, ponytail swishing behind her. "You built this yourself?"

"Yes!" Seo said. Then, realizing she sounded like a too-eager kid, amended, in a more serious voice, "Yes, all of it — even the time machine part."

Jenny seemed fascinated. "Show me."

That set off the Seo ramble.

Alison listened with detached amusement, as Seo babbled and beamed and waved her hands around, jumping up and down just to emphasize her sheer brilliance in her achievements. Alison, of course, couldn't follow a word of it.

Jenny seemed to be following all of it, though.

"To the coupling circuits?" Jenny asked, eyebrows raising in alarm. "What, really?"

Seo faltered. "It… works!"

"It'd be phenomenally dangerous," said Jenny. She looked inside, at the wiring. "I'm surprised you haven't…"

She paused. Momentarily confused.

Then gave a small, "Oh," and poked her head out of the console. Examining Seo with a growing interest.

"What?" said Seo. She shifted uncomfortably. "What is it? You're not going to say it isn't brilliant, right? Because it is. And… and… I can always make it more brilliant, if I feel like it!"

"It's very clever," Jenny mused. "Extremely clever." Then, in a louder tone of voice, "Are you the only one that can fly this ship?"

Seo shrugged. "It's safer that way."

Jenny thought this through. Then shrugged. Went over to the coordinate panel. "Twenty first century Earth, right?" she said. Tapping in the numbers. "London? I think I know that one."

"You've been there?" said Alison.

Jenny glanced back, and shot Alison a look that warned her to be quiet and play along.

Right, then. Well, whatever Jenny was doing, Alison supposed it couldn't possibly do any harm. She seemed a reasonable enough person, after all.

Seo resumed her happy expression, and bounced around, sending the ship hurtling into motion. The landscape outside blurred, then tumbled into the colors of the vortex, as the ship spun backwards through time. Back… back…

"On our way!" Seo assured her.

Jenny regarded the vortex. Then Seo. "Yes," she said, sounding a little surprised. "We are. Interesting."

They land in a back-alley, conveniently out-of-sight, where they could be discreet.

"There!" said Seo. "London, 21st century!" She turned, then… hesitated. "Wait, this isn't London. This is Cardiff." Paused again. Then, "This is where I always land when I go to Cardiff!" Spun around to face Jenny. "How'd you know the coordinates for…?"

"You don't actually know the truth, do you?" Jenny said, softly.

Seo's eyes went a little wider. She fidgeted, her eyes flicking momentarily over to Alison, then back to Jenny. "Truth… about…?"

"The coordinates I gave you were for the distant future," said Jenny. "A planet called Seldor. You used those coordinates. And still came here."

Seo stared. Clearly confused.

Jenny went over to the central console, opened it up. "Thing is, there are two different time machines in here," she explained. Pointed. "That first one… well, it's extremely dangerous. Would certainly transport you through time but… use it too often, and you might tear yourself to shreds."

Seo crept over to Jenny. Peaked inside. But said nothing.

"Course, the power-core's burned out," Jenny admitted. "Should have made this whole ship unflyable."

Alison stifled a grin. Yep. She remembered who'd done that one.

"But that's what the coral is for!" Seo insisted. "It's to take the place of the power-core, so my machinery can…"

"Seo," Jenny cut in. "The coral isn't connected to the other machine."

Seo froze.

Jenny went over to the central console. Opened it up, again. And showed her. "This," pointing to one side, "is the TARDIS coral. And this," pointing to the complete opposite side, "is your setup. Completely different. And not connected to your machinery. The coral isn't working as the power source, because there is no power source. No piece of machinery in your ship, Seo, is meant to store and channel dimensional rift energy." She glanced up at Seo. "The ship itself technically shouldn't work at all. Except… it does when you use it."

"I don't understand," said Seo.

"It works when you use it," Jenny said, more slowly. "And only you. Just the same way that you — and only you — can override the coordinates subconsciously. By controlling the flow of energy."

Alison's jaw dropped. As she worked it out. "She converts and stores energy!" Alison cried. "And she's brilliant with rift energy, in particular. The TARDIS coral is using her to complete the circuit. That's why Oliver doesn't work for anyone else!"

Seo looked up at Alison. Still seeming lost. "But… but I built…"

"It's startlingly clever," Jenny noted, looking down into the machine, again. "With the TARDIS coral, you're connecting Seo to the ship, allowing her to work as the power source — in just small enough quantities that she doesn't even notice. The ship won't work for anyone else but her, and if someone hijacks it, Seo will be able to redirect the energy flow manually, to make sure it still goes to exactly the place she wants." She chuckled to herself. "Really, considering most of the time machine is just you and what's embedded directly into that coral itself… you don't need the rest of this at all." She gestured at the central console, then at the entire ship. "Only thing you need… is, well, you. And this coral. Long as you weren't in the vortex too long, you'd probably survive it."

Seo stared.

"And the non-coral time machine bits…?" Alison said.

"Don't do anything," Jenny replied. Shrugged. "Why would they? This is a much better system. And more clever." Jenny grinned, then clapped the top of the console back shut. Turning back to Seo. "Fascinating, isn't it? I'm so glad you showed me! I love working out mysteries like that."

"I… um…" said Seo.

Jenny turned towards the doors, and threw them open. "So let's see what it's like here!" she called back. "Come on!"

Seo lingered behind. Her jaw still dropped open.

"Seo?" Alison asked. "You all right?"

Seo jumped. Spun around, clearly looking rattled. Then planted a stubborn look on her face. "Yes. Yes!" She held up her head high, strutting to the doors of her ship. "I knew all that. I was just testing. I am clever, you know."

"I know," Alison assured her.

"And I did build it all myself," Seo added. "Doesn't matter if the bits I built didn't actually wind up making the ship go. I still built it, and that's impressive."

"I know, Seo," said Alison. "You don't have to prove anything."

"Just wanted to set the record straight, was all," said Seo. As she left the ship.