If it went bang, involved blood, or promised to unlock the secrets of the universe, there was sure to be a vampire around.”
-- Diana (chapter 1)

Importance: Diana has just seen Matthew for the first time. She has met vampires before and is describing the reason they are drawn to specific fields, such as particle accelerators and biology in modern times, and electricity and anatomy in decades past.

Light was seeping from Diana Bishop's body – all around the edges, escaping from her pores. The light was a blue so pale it was almost white, and at first it formed a cloudlike shroud that clung to her for a few seconds.”
-- Narrator (chapter 3)

Importance: Matthew is watching Diana sleep after meeting her for the first time. He is amazed by the power that radiates from her, even in her sleep, and believes that Diana does not realize how powerful she is.

On Monday I'd met a vampire. On...
-- Diana (chapter 6)