Who hasn't wished they had a secret, psychic bond with their bestie so they didn't have to bother trying to text each other in class? It's the stuff of dreams for most of us, but for Lissa and Rose, it's reality. Rose knows what Lissa is feeling, and she can jump into her BFF's head whenever she pleases—and sometimes even when she doesn't.
When the girls learn that St. Vladimir and Anna shared the same psychic bond, they're more than a little curious, but they're still not sure what it means, or why it started. Enter Victor. He might be a crazy, power-thirsty kidnapper, but he's also got a lot of knowledge. He tells Lissa:
"The accident woke the spirit in you; your fear over seeing Rose dead made it burst out, allowing you to heal her. It forged your bond. And once it's out, you can't put it back. It's a powerful element— but it's also dangerous." (22.38)
It might sound creepy, but we've seen this throughout the whole novel. We like to think of the girls' bond as a physical (or psychological) expression of their friendship—it's not just that they are guardian and Moroi, or two girls who like to hang out; these two are as close as can be and participants in a friendship that's the stuff legends are made of. It's important for us to know that the relationship these girls share isn't ordinary even in their magical world, and that's something worth fighting for.