From publisher blurb:
A Tale of Revenge and Blood!
The Trilogy of Blood is a trio of adventures designed for vampiric PCs of 5th level, using the rules for vampire player characters from the free Liber Vampyr: Secrets of the Blood, although the adventures are suitable for any evil characters of roughly 5th level. Originally developed to be run at Paizocon, these adventures put the PCs in the role of the only surviving members of the Red Circle, a secretive order of vampires who rule the city of Isport from the shadows. When unforgivable betrayal causes the rest of their order to be murdered by vampire hunters, the PCs must step up to take vengeance: first on the vampire hunters themselves, and then on the one who betrayed them. Over the course of the adventures, the PCs also grind all opposition to the Red Circle in the city of Sharsir into dust beneath their feat, and hunt down and kill an old enemy practicing dark rituals that are forbidden even amongst vampires. The book includes everything you need, including pre-generated characters.