How to save a dynasty: find the missing people, find the lost crown, and right the wrongs of the past.

The Briar Crown will soon receive a new owner, but Deyzi Domonov is determined not to let it claim her as its next victim. In order to do that, she needs to find its counterpart, the Tidal Helm.

But neither the helm nor the Waterborn population have been seen since the Fall of Eluha, when her great grandfather invaded the country, slaughtering the king and queen and ripping Domovnia apart. After finding her mother's journal, Deyzi decides to fulfil the late Queen's plans to excavate the only place they haven't looked, the maze of canals and caves that lie beneath the length of the country.

With the help of a renowned explorer, Deyzi descends into a dangerous world in search of a lost civilization, certain that they possess the item she seeks. But digging up the past uncovers hard truths about her own family, her country and the true purpose of their mission.

Meanwhile, their guide in the watery underworld is torn between helping the woman - with hair like the sun he has never seen - and handing her over to his people to break the curse that binds them.

As her search for the truth becomes a battle of survival, Deyzi must dig deep to save not only herself, but the people and country she loves. But can she do it without a Waterborn by her side, or will this be the end of the Domonov dynasty once and for all?