The Devotion of Suspect X

Yasuko Hanaoka, a divorced single mother, thought she had finally escaped her abusive ex-husband. But when he shows up one day, threatening both her and her teenaged daughter, Misato, the situation quickly escalates and he ends up dead on her apartment floor. Without hesitation, her enigmatic neighbor, Ishigami, a brilliant math teacher whose devotion to Yasuko runs deep, offers to calculate the perfect alibi. His one condition is that the two women must follow his instructions to the letter.
Detective Kusanagi of the Tokyo Police, faced with a brutal murder and evidence that doesn’t add up, seeks the advice of his college friend Dr. Manabu Yukawa, a brilliant physicist nicknamed “Detective Galileo.” Yukawa knows the math genius from his past, and what ensues is a fierce battle of wits, one mastermind against another, one using all his skill and wits to uncover the truth, the other risking everything, proving the depths of his devotion.
Tightly plotted, with one surprising plot twist after another, and sharply written, with characters that will stay in the reader’s mind long after the last page is turned, The Devotion of Suspect X shows why Keigo Higashino is the best-loved writer in Japan today.