Lullaby

Beautiful but deadly, their song won't let her rest

Lullaby is the second book in Amanda Hocking's Watersong series, a powerful story of magic, love and mystery in a world of sirens.
Gemma had to disappear with Penn, Lexi and Thea after a night of incredible violence on the island. She can still barely come to terms with her new affinity with the ocean - and the siren powers that go with it. Now she's been transformed, Gemma has no choice but to leave all she loves behind. She swears she won't lose her humanity, but the call of the sea is maddening and compulsive.
Harper won't give up on her missing sister. The search draws her closer than she'd like to bohemian Daniel, but she could really use his help. They'd almost given up, until a small news item tells of a horrific murder in a nearby beach town, and Harper thinks she's found the deadly group. But can Gemma's curse be reversed - and what if she doesn't want to come home?