When Yoshitaka married his wife, Ayane, it was on the understanding that she would at some point become pregnant. It has now been a year of trying, and still no baby. Yoshitaka sees marriage without children as pointless, so he informs Ayane that the two of them are done. Not only that, but he already has another potential mother of his children lined up. Ayane appears to quietly accept this, but in reality she has decided to put a plan into effect, something involving white powder.
A short while after Ayane and Yoshitaka's conversation, Ayane leaves to spend some time with her parents and some old friends. She provides her apprentice, Hiromi, with a spare key, just in case. As it turns out, Hiromi is Yoshitaka's secret lover. Hiromi makes Yoshitaka some coffee, and the two of them contemplate their future together. All appears well until Hiromi tries to contact Yoshitaka before their next planned date. When she gets to the house, she discovers him dead. The police determine that that the coffee he made himself was poisoned, and it isn't long before they start digging into Hiromi and Yoshitaka's secret relationship together.
Hiromi had access to the house and had even used Yoshitaka's coffee-making supplies and equipment shortly before Yoshitaka drank his poisoned cup. However, she had no motive, and it's unclear how and when she might have added the poison. Ayane had a motive but was nowhere near her husband when the poisoning happened, and if she'd sabotaged any of the coffee-making supplies or tools, Hiromi should have been poisoned as well when she and Yoshitaka made coffee together. It's up to police detectives Kusanagi and Utsumi to figure out what happened.
I listened to the first book in this series, The Devotion of Suspect X, not too long ago. Although I never got around to reviewing it, I enjoyed it and was looking forward to this. Unfortunately, it didn't live up to the first book for a variety of reasons.
The two books had similar structures. Readers were given several key details about the case that the police would be unaware of and would have to find out on their own. In the first book, readers knew exactly how the murder happened, who committed it, and who was involved in covering it up. The question seemed to be whether the police would figure out the truth. In this book, readers knew that Ayane had to have somehow used the white powder to poison her husband. The question was how she managed it and, later, what her intentions were for Hiromi. Both books ended with twists that revealed that readers knew less about what was going on than they thought - those "key details" at the start of the books were only part of the overall puzzle.
The mystery of how Ayane arranged for her husband's coffee to be poisoned without killing Hiromi seemed overly simplistic at first but gradually became more complex, as the police found more and more places with traces of the poison but no definitive source, and no explanation for how Hiromi and Yoshitaka managed to drink coffee together earlier without both of them winding up dead.
When Utsumi involved Yukawa in the case, I wondered if Kusanagi and Yukawa would ever talk about the events at the end of the previous book. While the events of the previous book were alluded to - I'd recommend that readers new to this series start there, if only to understand the tension between Kusanagi and Yukawa - they weren't discussed in any sort of detail.
I was impatient with Kusanagi's attraction to Ayane and, like Utsumi, thought he was ignoring obvious clues in an effort to continue to view Ayane as innocent. I was actually a bit surprised that Yukawa didn't needle him over it, since his desire to protect Ayane was a bit hypocritical considering how the previous book ended.
Anyway, I had fun thinking through the problem of how Ayane managed to poison her husband, but the actual solution turned out to be a bit much. It would have taken a ridiculous amount of dedication - once the plan was begun, there was no going back and no telling anyone, and the slightest slip-up could have resulted in an unintentional death. The possibility for failure was huge and, in real life, no one would have gone through with such a plan. And the backstory for it all was kind of gross. I mean, I was somewhat sympathetic towards Ayane for a good chunk of the book - yes, she likely killed her husband, but he'd used both her and Hiromi, viewing them as nothing more than his future baby incubators. Once additional details were revealed, though, I found myself disliking most of the book's cast.
The very end of the book further soured it for me. While discussing the murder and everything that led up to it, Yukawa basically concluded that women are illogical. I would have liked nothing more than for Utsumi (a woman) to smack him at that point, but unfortunately that didn't happen. And honestly, I'm not any more pleased with Keigo Higashino if he thought "women are illogical" would make all the difficult-to-believe aspects of the murder mystery solution easier to swallow.
All in all, this was disappointing. I haven't decided yet whether I'll continue on with the series.
(Original review posted on A Library Girl's Familiar Diversions.)