It's all AU.

"I think he's in here." The Apprentice poked his head into the building, not as wary as Leela appeared to be, looking around curiously. "It's a little fuzzy, trying to see through the walls. It's better, because they're not all loud and don't make my head hurt and make me get lost because I don't like it loud, but it's harder if I want to find someone. Or if I want someone to find me. My teacher can always find me, though. She has a computer that tells her where I am. It's nice."

He stepped further in, looking around. It was a room full of books, and he peered around the shelves, looking for the one he could identify in his head as the Doctor, but not the same one as the one who'd taught him to make the walls around his mind. He beamed when he spotted a man with blond hair, and dressed in clothing he couldn't actully place in time and space.

"Here! I found him!" He looked over his shoulder at Leela, taking a moment to remember her name. He didn't think she'd told him. He looked back at the Doctor. "She sounds like a cat in the back of my head, hissing and threatening threats to the storm. And you sound like a storm, but not all dark, and not all fire and ice in one, but like distant storm and rain."

Leela had thought she was in the bowels of the TARDIS looking for something-or-other at the Doctor's request when she found herself in town. Arriving on a planet in any way was still new and unexpected, although so far that had generally involved the front door of the TARDIS. She set about looking for the Doctor or, if it turned out that way, whoever had detained him, knife at the ready, staying in the shadows of the buildings with a keen hunter's silence.