Blackwatch by Jenna Burtenshaw

Jenna Burtenshaw continues her dark fantasy trilogy The Secrets of Wintercraft with YA dystopian novel Blackwatch.
 
In Wintercraft, fifteen-year-old Kate Winters learned she was one of the Skilled, a rare person who can bring the dead to life. Even among that rare group, Kate is special. She alone can understand the secrets of an ancient book of knowledge.
 
In the sequel, Blackwatch, Kate is on the run from the Skilled, who have accused her of murder. And she is being hunted by an elite unit of assassins fighting in the war against Albion, Kate’s home.
 
When a potent magic threatens the veil between life and death, fate reunites Kate with enigmatic villain Silas Dane, a man who cannot be killed. Only they can save Albion.