There's a deep fairy tale element that Jaclyn Dolamore creates in Between the Sea and the Sky, that gives this story a very sweet feel to the whole, while going back old school with a nod to Hans Christian Anderson. Humans live along side mermaids who graduated to sirens, and the winged race of people. The book focuses around the life of Esmerine as she becomes a siren, and later tries to find her runaway sister Dosinia, whose sudden disappearance raises major red flags, and Esmerine is determined to find her. Along the way she meets up with an old friend Alandare, one of the winged race. Since they parted Alan has become a whole different person then the one Esmerine remembers. Nevertheless he's the only one who can help Esmerine find her sister. While it does starts off a tad slow, the story picks up as Esmerine starts her journey in finding her sister, with some nice twists and a easy plot to follow. The relationship between Esmerine and Alan starts off rough. With Alan pushing Esmerine away due to the strain his father has him over. There's a nice build up as they reestablish what they mean to each other and finding an a newer adult love then the child's love they once shared. The world the mythology is build on plays on Hans Christian Anderson's tale with the pain mermaid suffer when they have feet, to the winged people and humans stuck in the middle. I would have loved to have a bigger view of the world, but were only given a small glimpse of it. The story flew with a truly happy ending that will leave a smile on your face long after.