The symbol of Chabucu

Chiara Smith is starting the year at a new school and has much to learn about it.One night she receives a letter from an anonymous person at her school marked with a mysterious symbol. The next day at school when she opens her locker she see's the same symbol carved on her school yearbook in what seemed to be red paint but looked more like blood...
This symbol is the symbol of a famous terrorist gang who wants revenge because of her dad being the owner of the anti-terrorist agency in Seattle.