Fifth Sin

Morally Gray Vigilantes, Found Family of Killers, M/M/M/F Polyamory, D/s Vibes, Enemies to Lovers, Trauma-Bonded RedemptionFBI agent Riley Carson has spent years chasing ghosts—three masked killers who hunt the monsters justice can’t touch.When he finally finds them, they don’t kill him.They chain him up.And make him question everything he thought was true.Drawn into their world, Riley is forced to face the darkness within himself—especially when he meets Fifth Sin:Allie, the siren with a scalpel and a taste for blood.Everett, the violent bruiser with a good heart and a filthy mouth.Nico, the quiet, enigmatic man who owns them both.What begins as obsession turns into something far more dangerous—discovering he has more in common with the monsters than the righteous,and possession that looks too much like love.Dark. Addictive. A high-heat romantic thriller about obsession, surrender, and the people who find belonging in the darkness.