Broken Fate (Threads of the Moirae, #1)

Zeus gave her one simple job: Kill every human. Atropos-daughter of Zeus and the third goddess of Fate from Greek mythology -spends her eternal life snipping human lifelines when their mortal lives are over. As if being a killer doesn't make life miserable enough, she and her Fate-wielding sisters must live amongst the humans on Earth thanks to a long-running feud between their mother and Zeus. Living on Earth means they must mingle with the mortals, attend the local high school, and attempt to fit in-or at least not stand out too much.

Killing and mingling don't mix, which is why Atropos' number-one rule is to avoid all relationships with the humans. Caring for the people she has to kill is a fast track to insanity. However, when Alex Morgan walks into her first-period English class, she knows she's in for trouble. He's the worst kind of human for her to like-one with a rapidly approaching expiration date. And he makes Atropos want to break all the rules.