What is the theme of the book The Looking Glass Wars

Revenge is a theme that motivates many of the characters in this novel. There is the note of revenge that raged between Genevieve and her sister, Redd, when Redd was disowned and passed over for queen because of her refusal to embrace the traditions and White Imagination of her family. Redd was angry and embarrassed by her mother's decision, therefore she killed her mother and tried to take the throne anyway. Genevieve fought her and won. To get revenge, Redd raised an army and built an invincible assassin, The Cat.