Melanie sometimes says, ‘I won’t bite.’ She says it as a joke, but Sergeant’s people never laugh. Sergeant did once, the first time she said it, but it was a nasty laugh. And then he said, ‘Like we’d ever give you the chance, sugar plum.’”
-- Melanie and Sergeant (Chapter 1 paragraph 22)

Importance: This quote is significant because it illustrates how little Melanie understands about what is wrong with her at this point in the novel, but how well she hits the nail on the head concerning what scares the sergeant and his people the most.

You don’t want to get attached to them,’ he says. ‘You know what they’re here for.’”
-- Sergeant (Chapter 2 paragraph 21)

Importance: Parks chides Justineau because he believes she is developing relationships with the children who are on the base for research purposes, and are dangerous.

And even though the smell was very faint where Melanie was, it made her head swim and...
-- Narrator (Chapter 2 paragraph 24)