In this story, August is a vampire who must kill to survive and he doesn't like it. He has even tried to kill himself, unsuccessfully, to stop the killing. The only way to stop the killing is to find his blood mate, a woman he cannot enthrall and convenience her to willing give herself to him. The problem is, when he finds her, she is happily married to her soul mate.
August then does some really dumb, human male type things to win over Nichole. August isn't able to enthrall Nichole, but he can enthrall her husband. He forces the husband, Dominic, to no longer love his wife. August is hoping that if Nichole feels neglected, she will give him a chance. After months of neglect, and Nichole still loves her husband, August decides he can't wait any longer. He kidnaps Nichole. This is when things start to turn dark. There is are some scenes where Nichole is put into an insane asylum against her will and it isn't a good experience.
If you've ever read a book by Kitty Thomas, you know that she writes some pretty dark books. The stories always have some sort of kidnapping or non-consensual or coercion into sex. This story is no different, but is lighter than most of her stories. It also isn't heavy in detailed sex scenes as some of her previous book. I don't feel that either of these depletes the story in any way.