Osric is a member of the Fyren Order, a guild of assassins who gleefully murder for money. Aurienne is a Haelan, a scholar-healer whose Order’s motto is Harm to none. When Osric first bribed Aurienne to heal him, he never imagined those lines would begin to blur. But every healing session draws them closer together. He finds himself developing unwanted feelings for Aurienne as her capable hands heal his body—and his heart. Aurienne’s perfect life has been flung into chaos in the form of a devastatingly handsome assassin. She should be in her research lab, not illicitly healing a Fyren every full moon—nor wrestling an attraction to him that threatens to slip into something else. Things go superbly sideways when Osric and Aurienne discover more about the deadly Pox deliberately unleashed through the Tīendoms. The plague may be the work of another Order—an Order far nastier than either of them can handle. As the lines between Osric and Aurienne continue to blur, the balance between peace and war, and love and hate, trembles, shifts, and hinges on a heartbeat.