In The Devotion of Suspect X (2011), by Keigo Higashino, when Yasuko’s abusive ex-husband shows up at her apartment, they get into an altercation and he ends up dead. A single mother, Yasuko plans to turn herself into the police but worries about the effect this would have on her daughter. Help, however, comes from a surprising corner: Yasuko’s next-door neighbor, math teacher Ishigami, who overheard the crime and offers his assistance in covering it up. When the body is eventually discovered, police detective Kusanagi is certain that Yasuko must have been involved in the murder, but her alibi seems too perfect to be real. Kusanagi asks his friend Yukawa, a physics professor and sometimes police consultant nicknamed “Detective Galileo”, for help. As it turns out, Yukawa and Ishigami are old classmates, and when they reunite Yukawa suspects him almost immediately.
What follows is an intricate game of cat and mouse, with many unexpected twists and turns. The characters are just as expertly crafted as the plot, and the writing is tinged with dark humor. I would recommend it to anyone who enjoys psychological suspense with a well-thought-out puzzle-box plot. After you finish this one, there are four more in the series.