Thicker Than Blood - Angela Roquet

Where there's a devil, there's a deal.

With her home and heart in ruins, Jenna is none too keen on the idea of helping the Duke of House Lilith-the man she holds responsible for everything wrong in her life. But when the Vampiric High Council summons Ursula, Duchess of House Lilith and Jenna's unsuspecting grandsire, to a trial where she's to stand accused of murdering her sire and abandoning her depraved scions, the duke is eager to strike a deal. If Jenna helps him protect Ursula, he will keep her darkest secret and put in a good word with the adoptive sire the queen assigns to her. Oh, and return her guns-provided she doesn't use them on him.