Bleeding Outside the Lines by Jess Allen

Ruby is a hired killer. Trained from childhood to be empty and detached, she’s never known what love is. It’s not allowed. But when someone close to her questions the person she’s become, Ruby’s convictions begin to waver. With her guard already down, her latest mark, the handsome Cassius Cross, seizes the opportunity to infiltrate her heart.
Cassius is not a good man, he has secrets and vices, one of which has put a price on his head. Desperate to discover who hired the beautiful assassin, Cassius fights back. But he’s quickly enamored by the woman keeping him in check and finds himself fighting for her instead.
Will Cassius capture Ruby’s heart? Or will she go for the kill?

This is a dark romance and is intended for readers 18+