Twenty-year-old Merena Boreas has had to fight her way tooth and nail just to survive the last seven years of hellish instruction provided by the Cardinal North and has earned herself the esteemed title of Captain, just in time to complete her eighth and final year.

But this year is no normal year…

This year the legendary Vault has unexpectedly arisen, offering a chance to catch the eye of a TideLord and secure her and her crew's future careers. Merena stands on the precipice of an opportunity like no other. She’s obligated to compete in the four deadly Pillar Trials against seven other captains from the three rival Cardinal Orders of South, East, and West.

But when you’re a castaway with no memory and a bastard’s name to boot… you’re also a target. A target for other captains—such as Captain Agni of the Cardinal South—the insufferably arrogant highborn who is every bit as ruthless as he is powerful.

It’ll take more than just her rare elemental affinity to win The Vault, let alone survive each deadly trial.

Yet, with every day that inches past, something haunting is being whispered along the sea breeze. There’s a darkness beginning to press into every corner of the Cardinal North's daunting fortress. It’s presence amplifies the wild and unruly beating coming from behind that wall of ice inside.

Something is coming.

A warning?

A message?

A memory.