Heart of the Drowned: When a Sea-Glass Heart Binds Two Enemies into One Fate. The Red Tide Prophecy, #1

The sea has never been merciful, least of all to Seren, heir to the Ocean Throne, born with the rare and perilous red scales-scales whispered in ancient lore to possess the power to call a soul back from death. To the merfolk he is a living miracle, to humankind he is a coveted weapon, and to himself he is nothing but a curse he never chose. Years ago, a human boy saved him from drowning in a forbidden inlet; in return, Seren placed a clear sea-glass core within the boy's heart, granting him the ability to breathe and move underwater without magic.
That boy, Aland, has since grown into the kingdom's most formidable young general, a warrior tasked with leading mankind's brutal campaign to eradicate the mer. He has no memory of the merchild he once saved, nor any understanding that the sea-glass core in his chest has begun to fester into a dark curse-one that consumes his life a little more each time he slays a mer under the king's command. When Aland finally collapses beneath the weight of the curse, Seren is forced into the cruelest twist of fate: he must save the very human who threatens his people.
To keep Aland alive, Seren tears a red scale from his own body-an act agonizing enough to stop a heart-restoring the life of the enemy he should have let die. Bound unexpectedly by blood, magic, and an old connection one remembers and the other has forgotten, Seren and Aland are driven together on a journey to unravel the truth behind the dying sea-glass core, the king who trains dragons to hunt the merfolk, and the ancient Lightning Scepter capable of killing dragons with a single strike.
But the deeper they travel into secrets buried by war and prophecy, the further their enmity bends into something far more dangerous-a pull neither understands, and neither can resist. Seren must choose between protecting his ancestral realm or the human whose heartbeat now echoes inside his own through the unstable bond between them. Aland must face the devastating truth that the power killing him may only be reversed by the mer he is forbidden to desire.
And when the first crimson tide rises to destroy the human coast, both must confront the question that will determine the fate of two species: If saving him means betraying the world, will he still choose him? In a realm where prophecy shapes the tides and destiny binds two enemies tighter than breath, the Heart of the Drowned may be the only force capable of rewriting the future-though its price may be nothing less than both of their hearts.