Lovely Wicked Things by Trisha Wolfe

The third and final installment of the Hollow’s Row series.

Halen:
I’ve created a monster.
When past and present collide, the fallout feels like the death of my morality. Every time I look into Kallum’s clashing, feverish eyes, I see a dark omen—the threat of what we’ll do to each other if our desires run wild.
While the Hollow’s Row case comes to a head, a new heinous player enters the scene. As the Alchemist threatens the town, I’m torn between a promise to help my friend, and my loyalty to Kallum—the man who has sacrificed everything for me.
I’ve created a monster—but he’s my monster. And if I can’t control Kallum’s chaotic nature, I’ll lose him…just as I’ve lost everyone I’ve loved.
There could be a future for us, but only if we don’t damn ourselves first.

Kallum:
The moment Halen St. James crashed my world, I made a vow to harbor her darkness, the lovely spark who ignited my black soul. But now, it’s time for Halen to finally step out of her shadows.
I would do—and have done—anything to keep her mine. I’ve become a villain to protect her. Even from herself.
When she looks into my eyes with recognition, I’m a man reborn, redeemed by her cleansing fire. Only there’s a vital piece of our story missing, and without it, I’ll always fear losing her—a primal fear that provokes the demon within.
The truth lies somewhere in the murky marsh waters, where killers and philosophers intwine, obscuring ancient wisdoms and feasting on the sweetest nectar.
I was created for her, to devour her heartbreak, and she was designed for me, the muse to the devil himself.

CW: Full list can be found on author’s website.