It's all AU.

After leaving the restaurant, Corwen had set out for a walk in the early evening air. She was pleasantly merry from the wine at the meal, and, well, wanted to make the most of the gorgeous frock the Doctor had rustled up for her. It was about time she got to explore a little, and see what and who else was around here. So when she saw someone up ahead, she caught them up, and dropped into step beside them.

"So, fancy a drink?"