I won this book on Goodreads' First Reads giveaway. Thanks Goodreads! 
 Keigo Higashino won the Japanese equivalent of the National Book Award and the Man Booker Prize for this book, which is essentially a psychological crime thriller. The premise of the book is at first deceptively simple. A single mother kills her scumbag ex-husband in what is mostly self-defense. After the murder, as the mother and her teenage daughter stand there stunned, not knowing what to do next, the next door neighbor (a brilliant mathematician who happens to have a crush on the single mother) offers to help in the cover-up. There is a secondary storyline of the two police detectives (plus a physics professor who occasionally helps out in police investigations) who are investigating the murder. 
 This was a very very fast read for me; the book went down smooth like milk. I only have a few minor complaints, namely that the characters don't feel as fully fleshed out as they should have been. There could have easily been at least a hundred more pages for character development. But still, I give it four stars for entertaining me from the first to the last page.