In a glittering underwater world, nothing is as it seems...

For the past twelve months since her parents' death, seventeen-year-old Miranda Sun has harboured a dark secret — a secret that has strained the close relationship she once shared with her older sister, Lauren. In an effort to repair this broken bond, Miranda's grandparents whisk the siblings away on a secluded beach holiday. But before Miranda gets a chance to confess her life-changing secret, she's dragged underwater by a mysterious stranger while taking a midnight swim.

Awakening days later, Miranda discovers that she's being held captive in a dazzling underwater city by an arrogant young man named Marko...the King of this underwater civilisation!

Nineteen-year-old Marko intends to marry Miranda in order to keep his crown from falling into the sinister clutches of his half-brother, Damir. There's only one problem: Miranda is desperate to return home to right things with her sister and she wants nothing to do with Marko. Trying to secure her freedom, Miranda quickly forms an alliance with Robbie — Marko's personal guard. However, she soon discovers that even underwater, people are hiding dangerous secrets...