I have just finished reading this. It is without doubt the best book I have read in years and years. Unfortunately it, and everything else this author has written, seems to be in an ebook format only so I can't lend it to all of my friends!
The book is about adult twin boys and their (extremely) dysfunctional relationship with each other and their parents. It's very dark, a page turner and I finished it in two days flat. I won't say more than that about the plot in case any of you want to read it yourselves.