Bloodline (Wings in the Night #16)

When Ethan discovers the terrified woman hiding on his ranch, he knows immediately not only who she is, but what. He's never forgotten her, not in all the time since he escaped their joint prison, a clandestine CIA facility where humans are bred into vampires willing to kill on command. He refused to accept that fate, and since he won his freedom he's become a legend to those he left behind. With her own escape, Lilith has become a legend, too, and now—together—they have no choice but to fight those who would become a legend by killing one.