Grab your running shoes, because Rose and Lissa have escaped St. Vladimir's Academy and are on the run. We're not sure why they've escaped, but they've managed to stay under the radar for two years. One night, they're luck runs out when a group of highly trained guardians shows up and takes them back to the academy. Once there, the girls get the normal lecture about how they broke the rules and are in big trouble; Rose takes the brunt of it because she's the dhampir, supposed to protect her Moroi princess at all costs.
She was protecting her by taking her away from this place, Rose retorts, but no one agrees with her. Headmistress Kirova only lets her stay at the academy at all because Lissa's uncle—Prince Victor, that is—stands up for her, and a guardian named Dimitri offers to train her so she can catch up with all of her classmates. There's only one catch: she's got to stay out of trouble and is pretty much on house arrest aside from school and training. It's not the greatest, but she'll be okay as long as she's with her BFF Lissa. By the way, did we mention these gal pals share a psychic bond and Rose can read Lissa's thoughts and emotions? They're not really sure why or how, but she can.
It's off to classes for the girls, who quickly settle in with the gossiping and social crowds from before they left. Since Lissa is a royal, everyone wants to be her friend to get in with the in crowd, but Lissa hangs out with a social outcast, Christian, and her cousin, Natalie. Things are pretty normal until one day Lissa finds a dead fox in her bed. Ew. The girls aren't sure who would do something like that, and it reminds them both of when Lissa healed a dead raven in the woods. Wait, what?
The girls aren't sure how Lissa did it, but she reached out to the dead bird and—kazam—it was alive again. Their teacher at the time, Ms. Karp, warned them not to tell anyone about this… ever. Um, okay. As Rose starts getting stronger in her training, she starts learning about the school's patron saint, Vladimir, and his shadow-kissed sidekick guardian, Anna. It turns out he healed people, just like Lissa. They have another similarity, too: Vladimir was kind of insane—literally—and Lissa gets super depressed easily and cuts her wrists sometimes. Rose wants to help her, but isn't sure how.
Before long, the rumor mill is spinning with lies about Rose being easy to hook up with. She's embarrassed, but mainly because her trainer, Dimitri, seems disappointed in her somehow. He's a strong, non-emotional type, and she's shocked he even cares, but he tells her in order to be a guardian, she can't go frolicking around drinking and having fun all the time. Lissa's life is in her hands, and it's on Rose to protect Lissa from any attack from a blood-thirsty, immortal Strigoi. Rose gets it and starts becoming more dedicated to her training… and to Dimitri. It's not just combat she wants to do with him. Hint, hint.
More dead animals show up in Lissa's stuff, and Rose is sure someone knows about her BFF's magical healing abilities. She lets Dimitri in on Lissa's cutting secret, in hopes that they can help her, but Lissa doesn't see it that way and gets ticked at her friend for sharing her secret. They're still mad at each other at the school dance.
When Lissa is kidnapped by a group of guardians, Rose rushes to help. But when she goes to Dimitri, before she can tell him what's happening with her friend, she kisses him… and then she's sure she's ready to lose her v-card to him, when—boom—just like that, a spell is lifted. Phew. She remembers why she's there and that Lissa needs their help. They gather a team and go to a cabin in the woods to get her, where Victor—Natalie's father—is holding her hostage in hopes that she'll cure him from a disease so he can take over and rule. Natalie saw Lissa heal the raven a few years back, so he's been sending her dead animals to see what she can do. There's something else, though: he knows she brought Rose back from the dead in the car accident they were in a few years ago that killed Lissa's parents and brother. She can do what?
Lissa escapes but in the shuffle, Christian gets attacked by computer-programmed hunting dogs called psi-hounds. Rose can see how much Lissa wants to heal him, so she gives her blood to her BFF so she can have the strength to heal Christian. With everyone healed and Victor locked up, Rose asks Victor why he did this. It turns out, he wants to start a revolution where Morois aren't just guarded by dhampirs, but have strength and training of their own, too. He also tells Rose she's shadow-kissed because she crossed over into death and came back. Victor believes so much in his revolution that he got his own daughter, Natalie, to change into a Strigoi to help him.
Natalie starts fighting Rose, but Dimitri kills Natalie just in time to keep her from hurting Rose. He does love her, but he just doesn't want to, because his #1 job is to protect Lissa, not Rose. Lissa decides she can't use her healing magical abilities anymore since it was making her depressed, so she stops the magic and starts dating Christian. Rose is happy to see her friend back to normal and safe, and above all else just hopes she can be strong enough to protect Lissa. It's going to take a lot of sacrifice, but she knows she's got to do it.