Lu never disappoints with her world building. This is definitely an intriguing world and as a previous ASL student I love that she incorporated a sign language in her novel. Many of the characters survive the ravages of war through the use of sign, and I love that this unconventional aspect was included as a crucial aspect of the book.
I enjoyed the characters relationships and the strong emphasis on family. While this book does have a romantic element, it does not override the entire novel, friendship and family, especially family that the characters choose is the main love element.
It is definitely a plot driven book as most of Lu's novels tend to be. That is not a criticism, but a fact. I love plot-driven, just as much as character-driven. It is fast-paced and held my interest. The scientific elements were terrifying and I look forward to what the rest of the series has to offer.