Even though, as I told you, it was an empty room, some of the compositions I played got a better reception than others.
-- Ava (chapter 4)

Importance: In this quote, Ava tells Otto about playing theremin for Přemsyl. Notably, Ava does not mention Přemsyl by name when talking about her theremin playing. She describes her job as for Karel, heavily implying that she was hired to play theremin at night for Karel (not Přemsyl), which further amplifies Přemsyl’s erasure. This quote, however, reveals that empty room where she played theremin seemed to react to her compositions. Přemsyl is therefore active in this passage as the empty room itself. Although he does not exist according to Ava’s story, he is still somehow able to communicate his feelings about the music, adding to the atmosphere of fantasy and disorientation in the novel.

Xavier wouldn’t really have minded visiting...
-- Narrator (chapter 5)