In "Nighthaven," Aesira must navigate a world of vampires and assassins after discovering she has the power to fight the creatures she once feared. As she joins the League of Assassins, led by the dangerous Vander, she must learn to survive in a world where fear is forbidden and mercy is seen as weakness. But as she trains under Vander, she must also contend with the desire he awakens in her, knowing that the true threat might not be the monsters in the dark, but the man who teaches her to fight them.