"It's only words, and words are all I have, to take your heart away." —Bee Gees
This is not the type of crime/detective novel where the biggest mystery is who committed the crime, as it is already revealed to the reader since the beginning. Instead the reader is brought to wonder how Suspect X managed to conceal the crime and befuddle the police.
I'd actually already watched the Korean movie adaptation, Perfect Number, prior to reading this book. While some things are changed in that movie (for instance, the police detective and the professor who knew Suspect X in the past are combined to become one character) and I'd forgotten many details, I specifically remember one particular aspect of the suspect's method, a crucial aspect in misleading the police in the investigation. In spite of that I still found this novel quite enjoyable. Looking forward to read more from Higashino.