Crown of Salt and Bone by Katherine Quinn

A lost king. A deadly bargain. And the ultimate sacrifice.

After losing the love of her life on an island of horrors, Margrete Wood opens a portal to the Underworld. She’s claimed her full powers, becoming a powerful goddess, and she’ll use her new magic to steal Bash’s soul back from the realm of the dead.
Darius, the God of the Sea, has waited centuries for Margrete to return. She’s the reincarnation of the woman he once loved, and he’s hellbent on wiping away Bash’s memory. But the Underworld is filled with ruthless gods and corrupt bargains, and when Margrete makes a deal with the God of Death himself to get her king back, Darius agrees to help—for a steep price.
With monsters of the deep to slay and a death god to appease, Margrete is forced to work with her enemy before time runs out and everything she loves is destroyed. For good, this time.

The third book of this exciting fantasy trilogy is perfect for readers who love high-seas adventures, swashbuckling heroes, and forbidden, steamy romance. Fans of Danielle L. Jensen’s The Bridge Kingdom, and Sarah J. Maas’s A Court of Thorns and Roses will be enthralled.