Bloodlines by Richelle Mead

This is a spin-off to the vampire academy books. In the last few Sydney Sage is introduced. An alchemist, a group of humans that cover up vampire knowledge from other humans (with a lily tattood to each of their cheeks). The group also hates the creatures and find them disgusting. She was dragged into Rose Hathaway's (A dhampir. That's a half vampire, half human creation that has to protect the moroi) mess purely because she owed someone. Anyway she ends up sort of liking Rose. This ends up with her in serious trouble obviously. This is where this book starts. She's been in bad graces with her people since. In the middle of the night her father makes her get up for an important meeting (I hate this man) . At this meeting she finds out that the moroi (the alright vampires who can use magic) queen's sister needs hiding. Half of the moroi want her dead *shocked face*