The plot of Hideo Yokoyama’s Six Four begins in 1989, with the murder of Shoko, a seven-year-old girl. Fourteen years later the perpetrator has yet to be apprehended, and the case is viewed as Tokyo’s police force’s most damning failure. The commissioner of police plans to visit the home of Shoko’s father to pay his condolences, and to insist that the murderer will be brought to justice.

It’s an empty promise. The job of persuading the still grief-stricken father to allow the commissioner into his home lands on the desk of Yoshinobu Mikami, the force’s head of media relations. During this task Mikami comes across an anomaly in the old murder case, one that makes him realise that a police cover-up has been in place ever since.

Six Four was a major success in Japan, and is the first of Yokoyama’s books to be published in English. In Mikami he has created a most unusual protagonist: we’re used to detectives following clues, but a media relations officer? It gives the book a unique feel. We accompany Mikami on his dogged trek to interview one officer after another, as he meets blank stares, denials and outright lies.

But he never gives up, even as his personal life is tested by the disappearance of his own daughter, Ayumi. Layer upon layer of worry is added to the hero’s back: panic attacks, the hostility of the press as they fight for their own freedoms, the powers that be holding him down. His back bends and begins to break. Whenever he weakens, his daughter’s face hovers before him and he finds the strength to carry on.

This is a doorstopper of a book, crammed with detail, and the reader needs a bit of patience to get through certain passages. Could it have lost 100 pages? Probably. But the weight of the book is part of its appeal, and there are always fresh surprises to pull the reader along. Mikami’s impassioned speech on the telephone to a silent man who hasn’t left his room for 14 years held me spellbound. Yes, there’s a brilliant twist near the end, but the novel goes beyond such games, intriguing as they are.

The final pages remind us that the real answers are hidden below the bloodstains and fingerprints, and lie further away than simple justice or revenge. Compelling, complex, insightful: a book to be savoured.