The Devotion of Suspect X by Keigo Higashino (Detective Galileo #1) * * * * *

The Devotion of Suspect X by Keigo Higashino is my fourth encounter with this author, and once again, it confirms why his books linger long after the final chapter.

I came to this one in a slightly roundabout way. I listened to it as an audiobook, largely because it is one of the few Higashino novels translated into Hungarian. Unfortunately, it is now out of print, which makes it impossible to gift or easily recommend locally. That is a shame, because this is one of his most distinctive and unsettling novels.

The story centres on Ishigami, a quiet, deeply introverted mathematics professor, and his neighbour Yasuko, a single mother living a restrained, anxious life with her daughter. When a murder occurs early on, the book does something unexpected: it shows you far more than a traditional mystery would. This is not a question of who did it, at least not in the usual sense. Instead, the tension comes from how and why, and whether intelligence, devotion, and guilt can ever truly outmanoeuvre truth.

The investigation is led by Detective Kusanagi, assisted by colleagues, while the titular “Detective Galileo” is not a detective at all, but a physicist whose sharp, analytical mind cuts through the case from a different angle. Their intellectual duel with Ishigami is one of the book’s quiet pleasures; it feels less like a chase and more like a slow tightening of a net.

As with many Higashino novels, the plot is full of red herrings and moments where you think you understand the situation, only to realise you have been confidently wrong. The book is not long, only nine hours in audio form, but it feels long. There are stretches where you genuinely wonder where the story can still go, how all these pieces could possibly align. And then they do. From an angle you did not anticipate.

The ending is classic Higashino. It is not triumphant. It is not comforting. It does not leave you feeling clever for having followed the clues. Instead, it leaves you quiet. I finished it on a dark, foggy evening, walking home from work, and the atmosphere felt uncomfortably appropriate. This is a story that sits in your chest rather than your head.

At its core, this is not a mystery about crime, but about psychology. About devotion taken too far. About the idea that even when a murder feels almost justified, it never truly is. And about the unbearable weight of living with what you have done. Higashino returns again to the idea that good people can commit terrible acts, but that being “good” means you do not escape unscathed; guilt becomes its own sentence.

I do recommend this book, strongly, if you can get hold of it. It is not a cosy mystery, nor a puzzle-box designed to impress. It is something colder, heavier, and far more human. A story that does not ask you to solve it, but to sit with it.