Arcanum: Vervain

Detective Jonah Pierce has mourned his brother Riley's death for a decade, and he's never managed to heal. He loved Riley too much, and maybe in the wrong way. When a new rash of vampiric murders begins, Jonah's division Arcanum is called in to investigate. Sent to talk to a potential suspect, Jonah gets the shock of his life. But that's nothing compared to what comes later, when betrayal shows itself far closer than he ever expected.