It has been six months since ondine Kendra Irisavie arrived in Haverleau, the hidden capital of the water elemental world. Six months since she discovered her destiny as the sondaleur. Six months since a series of devastating events left behind their mark. Now, as she enters the chevalier elite program in her final year at Lumiere Academy, Kendra continues forward on her prophesied journey against the Shadow. Obsessed with what she must do to keep those around her safe, she struggles to balance her powerful magic and the demands of her fate with the challenges of friendship, the complications of romance, and the bonds of family. Meanwhile, the threat of the Shadow looms larger. Kendra and her friends investigate a series of puzzling human and elemental disappearances in the city of Lyondale and uncover a horrifying tactic used by the Aquidae in the war. When danger strikes close to home, Kendra must separate the truths from the lies and choose who and what to believe. Even if it means facing what she fears the most. Billow is the second book of the Ondine Quartet series (Whirl is book 1).