Close Kin (The Hollow Kingdom #2)

the long version

For years Emily has been living happily in the underground goblin kingdom. Now she is old enough to marry, but when her childhood friend Seylin proposes, she doesn't take him seriously. Devastated, Seylin leaves the kingdom, intent on finding his own people: the elves. Too late, Emily realizes what Seylin means to her and sets out in search of him. But as Emily and Seylin come closer to their goals, they bring two worlds onto a collision course, awakening hatreds and prejudices that have slumbered for hundreds of years.