Three Days later.

"Checkmate, Doctor."

"Hmm. I knew it was a mistake to teach you how to play chess!"

Parthenope grinned at him from across the table she'd created. "Why is that? Do you not appreciate a skilled opponent?"

"Skilled? I've lost the last four games! I should take you to Las Vegas. You'd probably be able to compute the odds on blackjack just as easily!"

She smiled, and he returned it. There had been no further discussion on the TARDIS, or his leaving, or her not trusting him. The Doctor treated her like a friend, sharing stories, telling jokes, listening to talk about her race and the great war that had destroyed all of them except her and the one who'd brought her here, the Psion whom he now knew had been her brother. She'd been hesitant at first, and he'd countered that by being supportive and encouraging. Almost unbidden, his mind went back to the night before, the night he had finally asked her for answers...

"It was horrible," she said softly.

He nodded. "I know. I've seen the results of genocide before."

"It was completely unfounded!" she cried. "We didn't even have space flight, no sophisticated technology. We had no desire for it. We were peaceful. All we wanted was to be left alone!"

"If you had no spaceships, how did your brother get the two of you here?" he asked, puzzled.

She sighed. "He teleported us."

"What?" the Doctor exclaimed.

"I didn't say we weren't powerful, Doctor. I only said we were peaceful."

He nodded again. His impulse had been to ask her if she truly thought that keeping him there was peaceful, but he quickly caught himself before he even opened his mouth. He was trying to understand, not attack. He had to earn her trust. It was his only hope of getting her to let him in so that he could undo the damage that had been done so long ago.

"Well, that was an impressive feat, to be certain," he said instead, thankful that she had agreed the day he went to her to stay out of his mind. "So what happened then?"

She tilted her head. "The planet was obliterated. The Psions were all destroyed save for me, I learned when you came."

"Yes, I know that. I meant, what happened to you and your brother when you came here?"

"I would rather have you tell me who killed my people," she said.

He shook his head. "I don't know."

She stared at him, anger beginning to show in her eyes.

"No, I swear to you, I don't," he said earnestly. "That isn't recorded anywhere in any history that I've read."

She still looked dubious. He sighed. "Do you want to rifle through my thoughts and see for yourself that I'm telling you the truth?"

She shook her head, slowly, but with finality. "No, Doctor. I believe you."

"I'm glad to hear it."

"I simply do not see how that is possible."

"It was a long, long time ago, Parthenope," he told her softly. "Long even by the standards of my people. It was many years before a ship happened across your planet. By then there was little left to go on. As you suggested, your people were not very technologically inclined. What I don't understand is... why didn't everyone do it? If your entire race could teleport-"

"I didn't say that," she answered. "My entire race, as you put it, could not teleport."

"Surely your brother wasn't the only one," he scoffed, then the look faded as he saw her face. "Incredible. An entire race of supremely mentally evolved beings, and only one with that power."

"You make it sound like there were billions of us, Doctor," she laughed without humor. "Perhaps, then, history does not know that there were only around a thousand of us on the entire planet."

His eyes bugged. "Only a thousand of you?"

"Yes, give or take a few of course."

He shook his head. "No. That I didn't know. Actually, there isn't much about that war that is known, Parthenope. Not that I'm aware of. As I said, there wasn't a great deal to go on when that ship arrived."

She snorted. "It was a bit more than a ship, Doctor. At least, from the images I got from the mind of your other self."

"What do you mean?"

She stared in shock. "You truly don't know?" Your other self did but you don't? How is that possible?"

"Well he does have an advantage of years on me," the Doctor said dryly. "It's obviously something he picked up, or something one of my other selves did. Now would you please tell me what you're talking about?"

She stared at him stonily. "That "ship" was a TARDIS."

His breath caught. "Not me," he said finally, quietly.

She shook her head. "No. Not you."

"Then who?"

"Who do you think, Doctor?"

"No," he said loudly, desperately. "Not-"

"Yes, Doctor. The Master."

He hissed.

"Believe me, I completely agree with you," she told him, anger evident in every syllable. "I would not be surprised if he'd had a hand in it somehow."

"A dirty, bloody, black hand," the Doctor muttered. Then he looked at her sharply. "It was no coincidence that he found you, then."

"Most likely not. I don't know how he knew I was here, but somehow he learned."

"The Master has ways of learning things," the Doctor whispered.

She nodded. "Well. To answer your question, my brother died after a time. I don't know what happened. And then I was left alone."

"All alone on a planet for years, decades, with no help, no way to leave," he said sorrowfully. "And then I came along, defeated the Master, told you I'd be back, and never returned." He smiled, a small sad smile. "No wonder you won't let me leave."

She looked uncomfortable at this, and he saw a glimmer of tears in her eyes. "I am tired," she said. "I think I shall sleep now."

He nodded, accepting her desire to end the conversation for the night. She turned, and he caught her gently by the elbow. "Stay here," he said quietly.

She was puzzled. "But you do not need sleep."

"I didn't say I'd be sleeping. I said I wanted you to stay here."

"Why?"

"Because you're obviously very upset right now and I'd feel better if you were here with me so I could keep an eye on you."

She raised her eyebrows.

"Please," he said earnestly.

She sighed, and for a moment he thought she would refuse and return to her retreat, stop speaking to him again. But she nodded. "All right, Doctor. I will stay and sleep near you."

She recreated her bed and slipped into it. By now he was convinced that she could only do this either with simple things or things that she knew what every part was and where it belonged. Otherwise she'd have made herself a TARDIS long ago. Wouldn't she? He thought. Surely she wouldn't just have stayed here because of... me?

"Good night, Doctor," she said.

"Good night, Parthenope," he replied. "Sleep well."

This morning when she had awaked she'd looked at him with astonishment written on every line of her face.

"What?" he'd asked.

"You didn't try to find the key while I slept," she'd said softly, wonderingly.

"No, I didn't."

"Because you knew I would know?"

"No. Because I didn't want to."

She said no more about it, only kept looking at him. The Doctor was hungry, and told her so; along with about half a dozen things he wanted to eat. Then he'd started teaching her chess. It hadn't taken long, and it hadn't taken long for her to start winning.

Now he was tipping his king over again and grinning. "How about we try something different?"

"Like what?"

"I'm open to suggestions."

"Well...can you swim?"

The grin returned even wider than before. "I think I can manage."