Lifethread — L.J. Charles

McKenna Fin is armed, dangerous, and in love for the first time. She'll do anything to earn her humanity... except the one thing the Fate's require. Stuck in her senior year of high school until she earns her humanity, McKenna Fin is responsible for cutting the lifethread of demons, and protecting teens from being possessed. To celebrate her fiftieth year of apprenticeship to the Fate Atropos, McKenna is given a new responsibility, and possibly a quick way to earn her humanity -- severing the lifethread of deserving humans. Her first assignment: Nathan Quinn. When Nathan becomes a primary demon target and gets sucked into Tartania, McKenna's duty as a Fated priestess demands she follow. McKenna can rescue him, no problem, but then she'd have to cut his lifethread. And he's the one and only guy she's been attracted to since forever. The demons consider Nathan one of their own and fight to keep him. The time limit on Nathan's life is about to run out, and McKenna has to make the decision: sever his lifethread, or battle demons, defy the Fates, and keep him for her own.