[She looks surprised and dubious when Ciel says he never had any intention of betraying Oz, like she doesn't know whether to believe him or not. If he's lying, then he's a very good actor - but then again, she's known plenty of good actors who do nothing but lie to everyone around them. It doesn't actually mean anything.

The next part though, that gets her to tense up.]

What does that mean? [Because she knows perfectly well what 'waking up' entails.] You're not planning on killing everyone here, are you? Use your brain! You should know by now they're messing with your head!