Ariel only wants to save her father. Instead, she catches the attention of Darien Blackwood—a ruthless mafia heir, brilliant surgeon, and a man who never lets go of what he wants. Now she's trapped in his dangerous world, where trust is a liability, secrets are currency, and disobedience comes at a price. But Darien has a reason for keeping Ariel close: Drug X, a mysterious substance whose creator is dead and whose secrets could change everything. He believes Ariel can lead him to it, unaware that her father's darkest secret may be closer than he could ever imagine. Darien is the kind of man Ariel should fear. Cold, calculating, and impossible to escape, he turns every act of defiance into another reason to keep her close. And as their dangerous attraction grows, Ariel must decide whether the man holding her captive is her greatest threat—or the only person who can protect her. Darien is hunting Drug X. Ariel's father holds the secret. And when the truth comes out, Darien may have to choose between the prize he's spent so long chasing and the woman he was never supposed to want.