[Baldr wasn't trying to overhear things, he swears. But he just happens to be passing by right as Keito starts to speak to himself, and he can't help but respond to those thoughts voiced aloud.]

I'm sorry... were I a mirrist, I would be able to do just that. [...] ... at least, I believe that I'm not a mirrist. It's hard to say for sure if it's true that our memories have been altered...