To complete her thesis, Marina teaches a black-tailed merman how to court a mate—only for him to reveal his true nature as a Siren and imprison her in the deep sea. When she finally remembers her childhood promise—“I’ll come back to see you every summer”—she understands why he has waited sixteen years. She once promised to return and keep him company. Now, with chains beneath the waves, he intends to make that summer last a lifetime.
