4 Book Set: Book One - Deep Blue (Paperback) Book Two - Rogue Wave (Hardback) Book Three - Dark Tide (Hardcover) Book Four - Sea Spell (Hardcover) The Waterfire Saga is a series of four books by Jennifer Donnelly about six teenage mermaids from different realms coming together to defeat a great and powerful monster named Abbadon. To do this, the six mermaids, Serafina, Neela, Ling, Becca, Ava, and Astrid, must find the six talismans that once belonged to the six rulers of Atlantis, their ancestors, and use their magic to finally rid the world of Abbadon. At the same time, a war between the merfolk is brewing, and the mermaids must decide who to trust before it's too late. Together they will form an unbreakable bond of sisterhood.