Is it love at first sight, or a gamble of fate?

Captain James Harlow, third son of a viscount, expects nothing from life and yearns for adventure. He gets his wish when he's overcome by a group of young miscreants with ties to the peerage, losing his hand in the encounter…and nearly his life. If not for a mysterious mermaid who emerges from the depths to save him.

Ione isn't like the other Nereids. Her scales and hair aren't as bold in color, and she has no desire to drown the mortals she mates with. So when a handsome mortal is left to die in the sea before her eyes, she can't stop herself from saving him—and trading her fins for legs to follow him on land.

With only three days to determine if they belong together, the pair are caught in the midst of a sociopath's schemes to tear James' life asunder.  But can the young marquess be stopped before he harms anyone else?