Onyx reviews: The Devotion of Suspect X by Keigo Higashino

According to an old saying: A good friend will help you move. A true friend will help you move a body. By any measure, Ishigami is a true friend to his next door neighbor, Yasuko, a single mother with a teenage daughter. At one time she performed in a night club, but she has reformed her ways and now works at a little shop that sells Japanese lunch boxes. Ishigami goes to the shop every day on his way to work, not necessarily because the lunches are special, but because the reserved mathematician is sweet on Yasuko.

Yasuko, on the other hand, barely knows Ishigami exists. She's oblivious to the fact that he comes mainly to see her, although her co-workers and bosses know.

She's been divorced from Togashi for five years, but he has tracked her down at her new place of employment and her home. In the past, he only showed up when he needed money, and Yasuko knows he's not likely to go away voluntarily. He also makes inappropriate comments about Misato, her daughter.

Togashi's death happens unexpectedly. It starts when Misato strikes him with a metal vase, which enrages the man, who then starts beating the teenager. Yasuko leaps to her daughter's defense, strangling him with a power cord. It's a messy death. Togashi fights back and Misato has to help her mother finish him off. Then Ishigami shows up at the door. Based on the assembled facts, he has deduced what happened. Though Yasuko considers turning herself in to the police, Ishigami offers an alternate solution. Leave everything to him, he says.

In a sense, The Devotion of Suspect X plays out like an episode of Columbo, where the audience is first shown the crime and then follows along as the detective gets to the bottom of the mystery. However, the perpetrator on that show was seldom sympathetic. In this case, readers may find themselves conflicted. The killing was self defense, though Misato initiated the conflict. Ishigami is a likeable enough fellow. He once had a promising future as one of Imperial University's best math students. However, fate and circumstance have placed him on a less than auspicious course. He teaches students who don't want to learn math at a college where the course is required but unappreciated. He spends his evenings working with pencil and paper on sophisticated proofs and theorems that may occupy him for decades. He's never been married, and his obsession with his neighbor surprises himself as much as anyone.

Professor Yukawa, a physicist at Imperial University, was a classmate of Ishigami's, though their courses diverged after the first year. They haven't seen each other in years, and are reunited when a third classmate, Detective Kusanagi, is assigned to investigate Togashi's murder after the body is found, mutilated, near a riverbank. Yukawa is Keigo Higashino's Sherlock Holmes character. The police consult with him on difficult cases, and refer to him as Detective Galileo. He is an astute observer, and formulates hypotheses that he tests via the scientific method. He holds his suspicions close to the vest until they are proven or disproved.

The book turns into a chess match between the two old friends, though Ishigami has no idea at first that Yukawa suspects his involvement in the cover-up. Yukawa knows how Ishigami thinks, so he understands the correct approach to take to unravel the seemingly perfect "proof" the mathematician created to mislead the police.

The story is complicated when Yasuko starts to see an old friend from her days at the night club. Ishigami's jealousy becomes obvious to her and she wonders whether she's traded one problem for another. Ishigami saved her bacon, but what does she owe him in return? For how long will she be in his debt?

Higashino is a master at plotting out nefarious schemes, and the truth behind Ishigami's manipulation of the circumstances surrounding Togashi's death, once fully revealed, will take readers by surprise. Ishigami scripted Yasuko and Misato's behavior in advance so they will know what to say when questioned, but what readers see is only the surface of his plan. Higashino lays everything out along the way, but still manages to pull off a brilliant and entirely plausible sleight-of-hand trick.