This book cover lies! Some guy at the Los Angeles Times called this book "A superb thriller... tantalizing," but I don't think he read the book.
Because Seicho Matsumoto's Inspector Imanishi Investigates, a.k.a. Suna no Utsuwa, a.k.a. Vessel of Sand as the book was called in Japan, is not a thriller. It's a police procedural and a very good mystery, but its pace is far too slow and it spends far too much time on cold leads and dead ends to be a thriller.