A centaur, a selkie, a fairy and a phoenix -- Helen has unusual friends. And in this incredible quest, they face some even stranger opponents, from mermaids to angry killer whales. Helen must help Rona the selkie to win the most important contest of the ocean world, and stop the deep sea powers from going to war. But who is trying to sabotage the competition and why? Can Helen and the fabled beasts find the real villain, and prevent the most devastating storm the world has ever seen?