The Cursebound Prince: A Dragon Shifter Romance (The Ravaged Kingdoms Book 2). The Ravaged Kingdoms, #2

Destiny has woven a path of adventure for Grace Holt, and her fate is about to send her into neck-deep trouble. Once content drifting through the quiet hours of her former life, Grace now stands bound to the mysteries of the Dreadwroughts and their unknown magic. Her royal lover, King Cassian, makes inquiries and discovers they aren't the only ones pursuing these strange objects. Across the waves, a desperate king has sent his envoy to the illustrious Runehold Conservatory, hoping its scholars can save his son-and his kingdom's future-from the Queen of the Sea.
An ancient allegiance between their realms draws Cassian and Grace to the storm-lashed shores of the seafaring nation, where peril rises and falls with the tide, sweeping them from towering cliffs to the crushing depths of the sea floor. Powerful magic stirs in the abyss, hinting at an ancient source, and they soon discover that nothing is as it seems. Amid crashing waves and veiled enchantments, Grace and Cassian battle relentless sorcery and monstrous threats in a desperate race against the gathering storm, and discover the blazing fire of a love forged in shared peril.