The Dutch Republic, 1650. One fine spring day in Friesland, twenty-year-old Clara van Wieren is faced with an ill omen: a whale, beached and rotting in the noonday sun. But Clara doesn’t believe in magic and superstition, and this portent is quickly dismissed when a proposal from a wealthy merchant arrives, promising Clara the freedom she seeks from her mother’s overbearing rule.

When her attempts at overseeing the household at the family’s estate lead to her chance encounter with a young man with russet hair and sparkling eyes the color of the sea, she finds herself strangely drawn to him. As Clara grows closer to Maurits, she must choose between the steady, gentle life she has been raised for and the man who makes her blood sing.

But Maurits isn’t who he seems to be, and his secrets, once hidden beneath the waves, threaten to rise up and drown them both. And when an ancient bargain, forged in blood between the mythical people of the sea and the rulers of the land, begins to unravel, Clara finds herself at the heart of a deadly struggle for power.