The Doctor chewed on her lip a moment. "Picked her up in 1941, spent a great few months adventuring with her and Roland, ended up on the Game Station, she died to give me time to get a Delta Wave generator finished, and I couldn't quite bring myself to use it. Roland figured out a solution, but humans aren't supposed to hold the Time Vortex like that, no one is, and I ended up with this body out of the bargin, and Jack ended up rather a bit more permanent than is entirely comfortable. I ran away, and she tried to chase after, but..."
She shrugged. "Just ended up at the end of the universe with Mark, my current companion, and Jack holding onto the outside of the TARDIS - she needed bearings, because Jack threw her all off. Ran into the Master, and she bloody stole my TARDIS, kidnapped me, and left Mark and Jack at the end of the universe and ended up here."
She pulled one hand out of a pocket, running a hand through her hair, bouncing agitatedly on her toes again. "Oh, I hope she doesn't do anything too stupid. I mean, it's bad enough she's gotten us lost outside of time and space, but it could be so much worse if she'd actually gotten what she wanted out of the bargin. She's intent on taking over the universe, you know. Probably a lot like her male counterpart."
She looked up at Kurt, a soft smile on her face. "For what it's worth, I'm sorry for whatever the Master did. Even if it wasn't the one I know who did it."