What is the main conflict in Frostbite by Richelle Mead?

In this novel, Rose Hathaway is still trying to catch up on her studies after going into hiding for two years with her best friend Lissa. On a trip to take an examination important to her studies, Rose and her advisor, Dimitri, discover the murders of a royal Moroi family and their guardians. These deaths spark fear throughout the Moroi community, causing St. Vladimir to decide to take all its students to a ski resort over the winter break rather than allow them to travel to their homes. Frostbite is a novel of friendship, love, and relationships that will entertain as it take readers on a new adventure in the world of vampires.