The Doctor found Seo huddled up in the corner of one of the rooms, knees tucked up to her chin, eyes darting around her, suspiciously. She tensed, the moment he entered. Then relaxed, as she saw who it was.

She looked away.

"You know how it is when time falls apart and the universe is in danger of collapse, don't you?" The Doctor sat down, beside her. "I saw it with the War. You saw it with… your own universe."

Seo nodded, faintly.

Her eyes haunted with the memory.

"Did you ask if you could change that?" the Doctor asked. "When you were a little girl? Did you want to go back to your earliest possible memory, and fix things?"

Seo said nothing for a long time.

Then, "He said it was impossible."

"Your… Dad," the Doctor clarified. "The person who raised you?"

Seo nodded.

"But your Dad still saved you," the Doctor reminded her. "Not everything. Not everyone. Just one person plucked from her rightful spot, and given a new life."

Seo dropped her head. Forehead resting on her knees.

"I did that with this planet," the Doctor said. "One planet. Plucked from the chaos. And saved. That's why it's here." He smiled. "And… I think… you're why we're here."

Seo didn't answer.

"The Time Lords used you to take us out of the universe and bring us to Gallifrey," the Doctor explained. "That means… they must have been trying to get you and me here, together. So you could help them return! Well, you are the Key, after all. Just a bit of cleverness, and I'm sure returning this planet to its normal spot in the universe would be…" He trailed off.

As he noticed her whole body trembling.

Gooseflesh dotting her arms.

"Seo?" the Doctor said, putting a hand on her back. "Are you… all right?"

Seo shot out of his grasp.

Plastered against the far wall, eyes wide and face terrified. Breathing, heavily, trying to quell the rising panic.

"Get away from me," Seo breathed.

The Doctor frowned, getting up to go after her. "Seo…"

"I said get away!" Seo screamed.

The Doctor stopped.

Raised up his hands, in placation.

"Right. Now… who are you, really?" Seo demanded of him. "Where are we? And what do you want with me?"

"Seo, it's me," the Doctor assured her.

He tried taking another step forwards…

And Seo clenched her hands into fists. Looking like she was going to deck him if he got any closer.

So he stopped.

"It's really me," the Doctor said, again. "This is really Gallifrey. Everything I've told you is the truth." He met her eyes with his. "You can trust me; I'm the Doctor."

Her hands shook. As the fists began to loosen.

And her fighting stance fell away.

"I… I…" She looked around herself. Shuddered. "I don't want to be alone here."

The Doctor swooped in, to comfort her. Shushing her, as he put his arm around her shoulders.

"It's a bit lavish, grand, and intimidating — but it's not so bad, once you get used to it," the Doctor assured her. Thrusting out of his mind all the very long days, in his youth, when he'd shouted at his tutors that it was the most rubbish planet in the universe, and he was going to steal a TARDIS and go exploring, first chance he got. "Don't judge on first appearances. It's… home. Well, my home. A home."

Seo said nothing for a long while.

"And… Romana?" Seo squeaked.

"Oh, she's certainly not one to be judged on first appearances!" the Doctor replied, with a laugh. "Old friend of mine — bit cold, at first, but you'll love her. She and I traveled the universe, righting wrongs, defending innocents, assembling the segments of the Key… to…"

The Doctor trailed off.

As the terror grew exponentially on Seo's face.

"Ah," the Doctor muttered to himself. "Right. Key."

Segments of that Key could be people, of course. The Doctor knew it. Romana knew it.

Seo knew it better than most.

"I've known Romana a long time," the Doctor assured Seo. "She doesn't run about, transforming people into stone segments. She turned the Princess Astra back into a person, after all! She respects the value of life." He pat Seo on the back, again. "Told you. I won't let anything happen to you."

Seo looked down at the floor.

Said nothing for a long time.

"I'm never going to escape this place," Seo whispered.

The Doctor frowned. "Sorry… what?!"

"I can just… feel it in the air," Seo said. Ventured another look around her, and shuddered, again. "This horrible place… it's the end for me. My tomb."

"Well, you're in a cheerful mood, today," the Doctor replied, also looking out at the surroundings. "Remind me not to take you to any other places I consider 'home'."

She snapped her head over to him.

Suddenly realizing what she'd said.

"I didn't… exactly mean it like…" Seo grimaced. "It's… a very lovely tomb?"

Right.

Looked like she wasn't in any mood to listen to his assurances that she was perfectly safe. And that he, most assuredly, wouldn't let her die, here.

Unless…

"Seo, do you… recognize this place?" the Doctor double-checked. "Is this 'tomb' bit some… memory breaking through?"

After all.

Glory had met her ultimate fate on Gallifrey.

A tomb, of some sort, for her.

"Recognize?!" Seo shook her head. "This place has been destroyed since before I was born! How could I recognize it?"

Right.

Fine.

Not that, then.

"But Terazina said…" Seo paused. Thinking it all through. "She knew… if I left to go back and fix history… I wouldn't be able to return. And the Glarnov's weapon seemed to think I wasn't long for the universe, either. Even you — back when we were banishing the spores — went on at me about dying too soon! And…"

She paused.

Then looked up at the Doctor. "I'm going to die, here," Seo said. "Aren't I?"

The Doctor sighed.

Looked like simply reassuring her wasn't working.

He was going to have to prove it.

"Tell you what," the Doctor said, getting up, "how about we both go, together, and speak in private with my good friend Romana? That way, you'll know she isn't out to kill you — and neither is anyone else, here." He held out a hand to her. "What do you say?"

Seo hesitated.

Then, with a deep breath, took the hand, and let him lead her away.