Joe and Leven were created in a lab to serve two very different purposes; save and slay. Joe has just one life to save, Leven has countless to end. Born as enemies, they share a brief but precious friendship before Leven’s refusal to submit to her creator throws both their lives into chaos. Years later, in the midst of a warfare that is eradicating supernatural beings at a vicious rate, Joe unexpectedly finds Leven. Still the self-sufficient girl he once knew he comes to realise that she is the lone assassin wreaking havoc with the shared enemy they want destroyed. Despite her resolve to stay alone Joe urges her to join his group of supernatural warriors; with her strength, skills and knowledge he knows that she could be the one thing that will help them win the war. But more than that, after all this time, Joe doesn’t want to lose her again.