Sinner

This novel follows Syn, a cynical vampire warrior who hides his secret double life as a mercenary from his allies. During one of his illicit hit jobs, he crosses paths with Jo Early, a human journalist who is completely unaware that she is actually a half-breed vampire on the verge of a lethal biological transition. As a powerful physical attraction sparks between them, they must navigate mutual trust while being thrust into the center of an ancient war.