The Wicked Sea

Mermaid Zephyra has shed her tail and is hiding on land in the kingdom of Mortia, stealing and bartering to survive while she runs from a dangerous captor from her past. When she is caught, the warlock Arion Stone sentences her to death.

He needs the God of Death's heart, which lies in a kingdom beneath the ocean that only the merrow can reach, so he offers a bargain: help him recover it and she lives. The bargain binds their souls, and the two enemies must learn to trust each other while Zephyra's pursuers close in.

The Wicked Sea is a dark, sultry enemies-to-lovers romantasy, the first book in the series of the same name.