Ylva looks between River and the apprentices, aware that this was probably a joke but also completely mystified about what it is, and unsure if she was expected to have got it.

Still, there are questions. These are totally valid questions and yet it involves poking at things that cause unpredictable responses in people. "Like silver or something, I get it. No, silver's fine. I'm, uh, adopted." There's a bit of a challenge in her faintly bared teeth.