Dragons of Wind and Waves — Susan Brown

Those twins stirred up a feeling of something scary, something evil. Something...dragonish. The word sprang unbidden to Margo's mind. And she, Margo St. George, had been born into a long line of heroes fated to protect their people from the ancient evil.When their mother disappears, twins Addie and Jacob Medway are carried off to the Nova Scotia town of Port St. George by their distraught father. But there's something weird about this town, something that is changing them. Addie experiences surges of uncontrollable rage and frightening blackouts; Jacob battles physical handicaps while struggling to keep their lives normal. And local mean girl, Margo, is haunted by her supposed family heritage as a dragon slayer. Caught between ferocious ocean storms and terrifying hunts for mythical dragons, all three teens must struggle to overcome fate and choose their own destinies in a world that seems to have no place for them.