[Ok, Luz's horror goes from a seven to a TEN. She had definitely knew this was coming, that it was a possibility since they were both in such a bad place, but actually seeing it was something new altogether. She knows it hits her Lance hard too, because he's spellbound now.

He must have known that he did this, right? But he's acting so shocked, like it was his first time SEEING it.

And once she hears the song getting close, she knows darn well they can't stay. Luz slams a glyph down and a vine stalk pushes them forward, farther from the approaching song].

Lance! We've gotta go!