Maggie Stiefvater has already mastered faeries and werewolves. But in "The Scorpio Races," she turns her sights to a more obscure supernatural creature -- deadly Celtic water-horses -- and wraps them in a story of blood, sea mist and windswept beaches. While the story itself is rather slow to unfold, it gives Stiefvater lots of time to flesh out her teen riders. 
 On a small Irish island, there is a special race every November. Many men and boys ride the capaill uisce (pronounced "copple ooshka") -- the swift, beautiful, bloodthirsty water horses, which want to either drown their riders or eat their flesh. They often succeed. 
 Puck is the first girl to ever enter the race, but terrible memories make her reluctant to accept a capall uisce, so she decides to ride her land mare, Dove. If she doesn't win, she and her brothers will lose their home. Sean Kendrick is a boy with a special knack with the capaill uisce. He catches, trains and sometimes kills the water horses, and no one knows their ways better than he does. 
 But as the race approaches, both the young riders are confronted by terrible problems -- the entire village is opposed to Puck racing, and Sean clashes with his cold, cruel employer over a prize stallion. And even as Sean and Puck grow closer, they begin to fall in love... but only one of them can possibly win the race. 
 "The Scorpio Races" is a story rich with Irish atmosphere -- salt spray, grey stones, ancient rituals and a tradition reaching back further than memory. And unlike most teen fantasies, this one doesn't have supernatural creatures who look like sexy teenage boys -- the capaill uisce are violent, wild beasts who crave blood and the sea, evoking both terror and awe. 
 Like her Wolves of Mercy Falls trilogy, Stiefvater alternates between Sean and Puck's perspectives, giving us different glimpses of their lives. The only problem with the plot is that it moves very slowly, but Stiefvater splashes it with stormy action scenes and a climax that races by at lightning speed. And her prose is simply exquisite -- one capall uisce is "a fearful dull Pegasus with disintegrating wings of sea foam" and teeth "the color of dead coral." 
 Stiefvater also crafts a pair of truly compelling lead characters -- Puck is a fierce, strong-willed young woman hurt by the loss of her family, and unwilling to let anyone tell her what she can't do. And Sean is a near-silent young man who has an innate touch with all horses, and a passionate connection to the stallion Corr. Their romance is handled delicately, with few words and lots of horse-training; it's also unusually complicated, since they both desperately need to win the race, but only one can. 
 While recognizable in its poetic prose and haunting tone, "The Scorpio Races" is unlike any other book Stiefvater -- or other paranormal-romance writers -- have ever created. Slow but sublime.