Well, this is a tough one to rate for me.
Firstly, I want to say that I loved the writing here. It was eloquent, flowing right, hitting me right where I wanted it to. So, that was not the issue.
I also liked the MCs. Dare, going back home after a wrong decision wrecked havoc with his life, has a hard time dealing with the fallout of his past actions. Alcoholism certainly plays a part in it, even though I felt like it was dealt with a little... off-handedly, maybe? Not sure that is even the right word, but I can't describe it better. I just didn't feel completely comfortable with it.
Same goes for the D/s scenes, or at least partly. Being drunk during a scene - a first even - isn't exactly my definition of safe, sane and consensual. Mainly because it seems hard to express your full consent when you're drunk off your ass.
Other then that, I'm a little torn on the rating. I liked Dare, but also had my tiny little problems with him. I really felt for him, that wasn't a problem. He just wasn't my most favorite person. Finn on the other hand, was a completely different ball game. I got a lot of his motivations and issues. His secret, though, was a little hard for me to swallow. I couldn't buy it 100%. Also, at times it felt like I was reading about two completely different persons, not one guy with a lot of baggage and personality traits.
I just don't know. It was good, but not really good. I liked it, but didn't love it. The writing was great, the mystery okay, everything was fine, but didn't sweep me off my feet.
So all in all, probably a 3.5, rounded up to 4 stars because I enjoyed parts of the story very much, just not all of it.