The heart-shaped amulet my father wears pulses faintly, as if in sympathy with the one hanging from my neck.

"What is that?" I ask, transfixed by the sight of it, though the answer seems obvious.

My father smiles. "Your mother had a mother of her own, you know. And if you think Meridia is powerful, Queen Salina was ten times so. This pair of amulets — mine, and the one now locked about your neck like a gilded collar — were a wedding gift, and a curse in disguise.

"A curse?"

"As is love itself, in some cases."

My father approaches as he speaks, and I keep my place, not wishing to betray my fear of him. He does not waste words, and if he meant to harm me, he'd have put his spear through my heart by now. Then again, I may not know my father as well as I thought I did.

"I was a young man when I met your mother," he says. "Already disillusioned with the ways of the world at nineteen, I sought my fortune upon the sea, and the sea proved a fine mistress, for a time. But as seems to be my fate in love, she betrayed me before very long."

He rests his hand on my shoulder, and I flinch. Up close, I see the lines of care around his aquamarine eyes, and the streaks of white in his long beard and hair.

"My ship capsized, and all were lost, save me," he continues. "A fair maiden of the waves spared my life, and with a single glance I fell in love with her — or fell under her spell, perhaps. Our courtship was brief, but fierce as forge-fire, and the choice she gave me was an easy one: forfeit all ties to the land and join her in the sea, or forfeit my love for her. I was several months shy of my twentieth birthday, and I thought I had seen enough of the human world to know its vices well. Struggle and strife ruled men's lives, and death by violence, illness, or slow decay was his sole deliverance. Compared to this bleak reality, the world beneath the waves seemed a paradise."

"And the amulet?" I ask, my eyes drawn to the red gem resting on his muscular chest. "What does it do?"

He sighs. "It and the one you wear form a single whole," he says, lightly touching it. "The Covenant of the Sea. It is a powerful and immortal spell, bound to the blood of the heir, passed down from Circe herself, if your grandmother's tales may be believed. Its purpose is to ensure that whoever holds the throne does so with full commitment. With a pure heart."

"A pure heart..." I echo, shaking my head. "What does that even mean?"

"It means you must find the one who makes your heart sing its own siren song; the one who sets your blood on fire and pulls at your passions as the moon pulls the tides. The amulet will know when you have found this one, and then you must choose where your heart truly lies," he says. "Love, or duty; land, or sea."

"That is what I came to tell you — or to tell my sister, rather," I say, turning to Natalis. "I have chosen land and love; I wish to abdicate my right as heir and pass it to you."

Natalis shakes her head. "It is impossible. Have you never wondered why no heir has ever left the sea? The land is not a choice for you, nor is the crown something you can give away. There is only one means by which inheritance passes from one heir to the next, and that is by death, Scyllian."

I frown. "The one I love is bound firmly to the land. He will not leave it, nor will I ask him to."

"Then your life is forfeit," my father says.

"What?"

He sighs. "Those bound by the amulet share a single fate. If their hearts are in accordance, and they choose the sea, then all is well. But if your lover will not leave the land, then you have a choice: free yourself by sacrificing love for duty and give your heart to the sea alone, or sacrifice yourself and free the one you love."

"Sacrifice..." Appalled by either possibility, I shake my head. "What if I choose neither? What if I refuse?"

"Then the amulet chooses for you," my father says. "If, by the next spring tide, you have not chosen, then the sea will reclaim the magic in your blood, and you will become as foam upon the waves, and salt spray upon the air. The sea will have you back, either way."

"I don't believe you," I say. "Mother would have told me this, if it were true."

"She would have, in time, Scyllian. She spent years searching for a way to end this cruel tradition, but the magic at its heart is original to her line. It is woven in the royal blood and bound to the throne. That is why I proposed a different solution: destroy the throne and end the rule of kings and queens. Replace it with a senate or a parliament; lift the burden of duty from one heart, share it among many, and seek the strength of the Supreme Council for additional protection."

He shakes his head.

"Perhaps when she was younger, your mother would have entertained such an idea, but by the time I proposed it, she had already committed herself to isolationism. Her power — the power bound to the throne — is what sustains the magic that keeps Thassos concealed, hidden in its own protective bubble. To end the throne would be to destroy these magics, and your mother... Well, she chose duty over love, at last."

"I don't understand. Why turn herself to stone? Why banish me at all?"

He smiles. "Because your mother and I love one another, even now: a fierce, terrible love. Those bound by the amulet share a single fate, remember. When she sentenced me to death, she believed she sentenced herself as well."

"That sounds... pathological," I say, grimacing. "Why not simply imprison you, then?"

"Because your mother is a complicated, clever woman. She wanted to 'have her cake and eat it, too,' as the landwalkers say. By sending one half of the amulet to the depths of the sea, and banishing the other half to the land, she thought to protect you from the curse, perhaps forever. By turning herself to stone she preserved her own life, if only what she thought to be the last moments of it, frozen in time, binding her power to the throne in perpetuity and thereby sustaining the magic protecting Thassos."

"What about you?" I ask. "If you've been alive this whole time, why have you not returned home? Why have you not revealed yourself until now?"

He smiles. "You're not the only one she banished, remember. When your mother placed that curse upon you, she placed it upon me as well, for I still wear the other half of that amulet. I, like you, have been unable to return home these many years. Unlike you, however, I lost the ability to walk on land long ago, when I gave my heart, in its entirety, to your mother, and to the sea. I have lived as a hermit, of sorts, content enough to let things lie and swearing your sister, here, to secrecy."

"What changed?"

He nods at my chest. "That. When my amulet awoke, after so many years lying dormant and cold, I knew it meant you had found love at long last. I've been trying to contact you ever since, to warn you; but while the world may seem small at times, it is still a large place, and it has taken me until now to find you. And now, I fear, by the span of a few short hours, I am too late."

I swallow. "What do you mean, 'too late?'"

Handing his spear to Natalis, he shuts his eyes, grasps his amulet, and lifts the chain over his head.

He holds it out to me. "I have not been able to take this off since the day your mother placed it about my neck, until now. The amulet has recognized a new heir, and the curse is yours. Yours, and the one you love. Now, you must make your choice."

I stare at the amulet but make no move to take it from him. The faceted gem catches the fractured moonlight glancing down from the waves above and seems to flicker with a mocking inner flame.

"There must be some other way," I insist. "You said mother was looking for a way to break the curse. Did she find nothing in all the years she searched?"

"The solution is as simple as it is impossible," he says. "Destroy the throne — the throne which only the rightful heir may approach, and which you may not approach until your heart is pure."

"Even if you could get close, what of mother?" Natalis asks. "Would you destroy her as well?"

My father nods. "Another impossible choice. You have the span of a month, Scyllian. Perhaps the answers that have eluded us below the waves await you on land; perhaps you will find your own solution. In the meantime..."

He places his amulet around my neck, so it lies atop my mother's. With a flare of light and a pulse of heat that makes me gasp, the gems fuse back-to-back, the two halves now one whole.

"Natalis and I will await you here," he says, "to greet you and your lover, or you alone; or, if such should be your choice, to take up the burden you have lain aside. Until then."

With a final salute of his spear, he and my sister turn and disappear into the blue depths once more, leaving me alone.

For a long time, I remain as I am, wondering if I've imagined the whole encounter. Only the gem, now no longer flat on one side but symmetrical and twice its former weight, convinces me I did not.

Dawn approaches, and I return to shore, my mind in as much turmoil as the retreating waves. As I emerge from the rolling surf, my fins giving way to human legs and my scales to smooth skin, I look up to see Martin waiting at the tideline. His face lights with wonder and delight when he spots me, and he waves.

I don't wave back; and as the amulet pulses with heat, my heart sinks as fast as the cursed stone would, if I dropped it over the deepest part of the sea.

I can't burden Martin with this knowledge; after what he's told me, I would rather die than cause him pain; a statement with newly added weight.

If my father spoke the truth, I've got a month to find a way to break this curse, or to make Martin stop loving me; neither of which I'm sure is something I can do.