The Wolf by Frost Kay

True love was a lie.

Betrayed by her childhood sweetheart, Scarlet is enslaved to the very creature who murdered her parents. With no options but to bow down to the wicked elf Arwen, Scarlet serves as her personal assassin to protect those she loves. That is until a ghost from her past throws her life upside down and endangers everyone she loves.

Escaping the criminals Brine called kin was the easiest choice he'd ever made. Now a Dark Court agent, his past catches up to him as his family's schemes endanger the new queen. Tasked with infiltrating Arwen's corrupt organization, Brine becomes what he was always meant to be - a monster. But everything goes sideways when he discovers his mate enslaved by Arwen, her hands steeped in blood as red as her cloak.

In a bid to keep them both alive, Brine strikes a deal with his human bride. One that could spell redemption or destruction for them both.