2 Works in Big Bang Big Bang
The Doctor and Rose end up taking the wrong type of vacation. Instead of fun in the sun, they cross paths with a physicist and his blonde friend who are trapped in a state of inertia unique to them. However, there’s a twist: Sheldon becomes the Doctor’s companion, and Rose stays behind to form a friendship with Penny. They come to realize that they cannot replace one another in time, or space.
Penny’s had enough of being a failure. If she can’t succeed at what she wants to, then damn it, she’s going to succeed at what she knows she’s good at. Written for the 2011 Big Bang Big Bang.