"When I said 'run', you did. Why?" The Doctor asked, genuinely curious.
"I just did."
He continued, "And when I asked you to come with me, you did." He'd thought this sover considerably. "Maybe not the first, time, but the second." He crossed his arms, and uncrossed them again, looking at her pointedly. "Why?"
"Because I trust you," She replied, grinning slightly, looking at the TARDIS console, running her hand gently over it.
"Why do you trust me?" He asked. "For all you know I could be some crazy person."
She looked at him, then. "But you have a... a..." She grasped for the word. "Tar... ta... TARDIS." She blinked, looking away briefly. "You can't be human."
"I'm not," He told her, like she hadn't already partially admitted it.
"I know. 'S alien, the whole thing. You, it--"
"She," he interruped quickly. "The TARDIS is a she."
"She." Rose nodded, thinking. "She..."
"Yep." He nodded, too.
Rose shrugged. "I guess... I just know I can trust you, because..."
"Because?" He asked her.
Rose shrugged again. "Just because."