Ronan Tideborn was abandoned as an infant because he bore no tide mark and could not breathe beneath the sea. Raised as a fish butcher in a remote northern harbor by the retired Sea Guardian Ulric Frostwave, he enters Mistport carrying half of a cracked conch pendant and saves the sister he has never met. A breathing pearl takes him through a tide gate into Atlantis, where his mother recognizes him but his father—the Lord of House Tideborn—refuses to acknowledge a landborn disgrace. When the Champion of the Seven Seas lays a golden trident at Ronan's feet, the truth begins to surface: Ronan carries the Heart of the Ocean and is the rightful heir to the Ocean Crown. To save his mother and the three sea realms, he must expose a false Ocean King, survive the Black Tide curse and prove that the ruler of Atlantis must be the first person willing to stand before the storm.
