The back cover blurb does a credible job at summing up the story so I'm not going to reiterate all of it - especially since I would tell you to keep away from this book. It will suck away your will to read.
As for me, I'm giving up on Foley until she ditches this series. I adore Foley, but I hate, hate, HATE the Inferno Club series, and this is the worst one yet! The hero and heroine lie to each other constantly. Carissa is a total gossip and Sebastian is a loveable rake with secrets. This could make for an interesting read with some great reparte, but instead we have secrets and lies and the hero and heroine mistrusting each other - and for good reason. I wouldn't trust Carissa as far as I could throw her.
Sebastian and Carissa had good chemistry in previous books, and at the beginning of this one even though it's a marriage of convenience neither seemed that upset about being married. No, real the real problem starts when you realize that Carissa is keeping a BIG SECRET and Sebastian is keeping a BIG SECRET - and yet neither has a good way of telling the other without disaster occuring. As the story goes on and on and they each dig themselves in deeper, and I didn't feel any connection to the characters except awkward discomfort.
Add to this mess the Inferno Club intrigue and I was uncomfortable, bored, and upset through most of the book. So that's it. I'm out. No more Inferno Club for me.
Bottom Line: Stay away. Stay far, far away. Even if you're an Inferno Club fan skip this one.