Night World by L. J. Smith
I've always enjoy reading the Night World series by L. J. Smith. When I first read it, it was something new perspective, which is the " Soulmate Principle ", so prevalent throughout the series. Even though the last novel, Strange Fate hasn't come out yet, that didn't stop fans to keep loving the series. More L. J. Smith on Simon and Schuster L. J. Smith Official Site Night World Wiki