The Devotion of Suspect X by Keigo Higashino

September 27, 2012

Plot summary (from the publisher): Yasuko Hanaoka is a divorced, single mother who thought she had finally escaped her abusive ex-husband Togashi. When he shows up one day to extort money from her, threatening both her and her teenaged daughter Misato, the situation quickly escalates into violence and Togashi ends up dead on her apartment floor. Overhearing the commotion, Yasuko’s next door neighbor, middle-aged high school mathematics teacher Ishigami, offers his help, disposing not only of the body but plotting the cover-up step-by-step.

When the body turns up and is identified, Detective Kusanagi draws the case and Yasuko comes under suspicion. Kusanagi is unable to find any obvious holes in Yasuko’s manufactured alibi and yet is still sure that there’s something wrong. Kusanagi brings in Dr. Manabu Yukawa, a physicist and college friend who frequently consults with the police. Yukawa, known to the police by the nickname Professor Galileo, went to college with Ishigami. After meeting up with him again, Yukawa is convinced that Ishigami had something to do with the murder. What ensues is a high level battle of wits, as Ishigami tries to protect Yasuko by outmaneuvering and outthinking Yukawa, who faces his most clever and determined opponent yet.

Warning: MAJOR spoilers below!


  • The writing was mostly straightforward and the plot unfolded quickly and logically.
  • Ishigami was a highly sympathetic character. I wanted him to get away with the crime.
  • I was completely thrown by the twist at the end: that Ishigami not only disposed of Togashi’s body, but also went and killed a homeless man to throw suspicion completely away from the Hanaokas. Wow, that really is devotion to the cause! I’ve read some other reviews that wondered why Ishigami had to kill someone else if he hid Togashi’s body so thoroughly. I think the answer to that is he knew Yasuko and Misato would not be able to hold up under rigorous police questioning. Thus, he gave them real alibis so all they had to do was tell the truth.
  • Speaking of, I didn’t notice that everything was a day off (the movie and karaoke alibi, I mean) until Yukawa pointed it out at the end. (Did Higashino specifically say at the beginning that Togashi was murdered on Monday, May 9? If not, then he didn’t really play fair in making the alibis for Tuesday the 10th, because the reader wouldn’t know it was a different day.) That was another great twist and showed just how thorough Ishigami was in planning the cover-up.
  • I liked that Ishigami accepted his fate at the end. When he was described as connecting the stains on the cell wall into matrices and color-coding them using only four colors so that the same two colors never touched each other (all in his head, of course), I knew that prison would be okay for him. He could sit there and do math to his heart’s content, which is a valuable tool for a prisoner. No one could contain his brain, as he so rightly put it.
  • I was wondering why Ishigami was so willing to risk his freedom and life to help save Yasuko. The interrupted suicide (he was about to hang himself when Yasuko knocked on his door to introduce herself as his new neighbor) was a very plausible reason.


  • I was unaware that this book was part of a series and that Yukawa was a recurring character. I thought Ishigami was the main protagonist, and thus the person I was supposed to root for. I didn’t like that Yukawa was smarter than him, or that Ishigami was caught at the end. It was sort of confusing to have the story told form Ishigami’s POV instead of Yukawa’s.
  • Yasuko Hanaoka was an annoying character. She was so timid for most of the book, yet readers are supposed to believe that she was capable of murder? The author gave zero indication that she had it in her.
  • The very lengthy scene where Yukawa visits Ishigami’s apartment for the first time was pretty boring. I ended up skimming most of it.
  • I hated that Yasuko turned herself in at the end. What a waste of Ishigami’s devotion!! Come on, I wanted something good to happen for the characters that I just spent all that time with! (See what I mean about the POV causing confusion in this book? I was rooting for the criminals, not the detectives.)


This was my first Keigo Higashino book, but it won’t be my last. The Devotion of Suspect X was a mostly compelling and entertaining read. I was on the edge of my seat trying to figure out what Ishigami’s end game was and what the details of his plans were, and I wasn’t disappointed by the reveals. I give this book 4 stars out of 5.

One Response to “The Devotion of Suspect X by Keigo Higashino”

  1. Why misoto attempts suicide ? Was that a reason Yasuko turned herself in ? This piece doesn’t fit and am scratching my head ever since I completed this book.

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