[She doesn't really register the tone, or even what he was saying, because she has definitely never seen anything like that outside of a movie or something, and her hand clenches on the doorframe, partly out of surprise, partly for greater support.]
How are you doing that? [She doesn't sound afraid so much as shocked, because again. Totally out of her realm of experience.]
action
How are you doing that? [She doesn't sound afraid so much as shocked, because again. Totally out of her realm of experience.]