Sydney is an alchemist, one of a group of people who practice magic and serve as a bridge between the worlds of humans and vampires. They protect the secrets of vampires and human lives. When Sydney is jerked out of bed in the middle of the night, she begins to think that she is being punished for her complicated relationship with Rose Hathaway. But what happens next is much worse. Jill Dragomir - the sister of the Moroi Queen Lissa Dragomir - is in mortal danger and the Moroi must send her into hiding.

To avoid civil war, Sydney is called upon to be Jill's guardian and protector, posing as her roommate - in a human boarding school -Palm Spring School, California. But instead of finding safety at Amberwood Prep, Sydney discovers that everything is just beginning.

Blood Ties contains everything: friendship, love, battles, betrayals that put this novel in the first place place in the New York Times bestseller "Vampire Academy" - this time she will visit vampire and human conditions, where the stakes become increasingly higher.