[ It's a joke that means something to her; she's been with him when something else was in his head, and she didn't like it. Although it was the only time 'he' said words that gave her a lot of material for reflection later. Trips to the moon are never dull with the Doctor. ]

The one with the sand shoes too?

[ Her eyebrows raise, but there's the ease of a smile on her lips. ]

So, theoretically, if we dig up the most disgusting thing ever to be buried then we should...we should stop moving in time, right?

[ Time Lord, help her. She couldn't hear everything, either, so she's putting pieces together. ]

This whole place operates like everything is expendable. Even essential body parts.