Voices, by Arnaldur Indridason (translated by Bernard Scudder)

It's Christmas in one of Arnaldur Indridason's Reykjavik-set murder mysteries: deck the skulls with boughs of holly. In Voices, Santa is found murdered in the basement of a posh hotel, an event that causes consternation, since this scarlet-clad symbol of universal jollity happened to have his trousers down. The manager is desperate to keep any whiff of scandal away from guests arriving to spend a cheery holiday amid reindeer and Icelandic hot springs.

His task is somewhat difficult. The deceased was wearing a condom, not part of the traditional gear, and on the bedside table in Santa's grotto is a history of the Vienna Boys' Choir. Inspector Erlendur, who became known to a wider readership when Indridason won the Gold Dagger for crime fiction last year with Silence of the Grave, is on another tough case. He doesn't make things brighter by refusing invitations to Christmas celebrations. His own idea of a splurge is to purchase a bottle of Chartreuse and sit alone reading about how Icelanders got lost and died trying to visit their loved ones in the festive season.

Erlendur persists with the hotel mystery, talking to the frail chambermaid and a seedy British guest. A picture of the dead man emerges that as usual with this deeply disturbing writer, goes far beneath the surface to create a story of suffering and loss uncovered by the police investigation. The dead man's interest in children did not stem from the obvious cause, nor did his relationship with his family follow a normal path.

Elinborg, Erlendur's female sidekick, is enquiring into a case where a small boy has repeatedly arrived in hospital with minor injuries, which give rise to suspicions of parental cruelty. The book is essentially about childhood: its abuses and their effects, the long-term damage suffered by a prodigy, the recollections that blight adult life. Indridason is particularly powerful on the intersections of the case with the investigator's memories. Erlendur, it transpires, lost a brother at an early age; his own drug-addict daughter is fragile and his attempts to get close to her founder.

The plot is not innovative, nor very credible: the solution to the Santa mystery dates back to Gaston Leroux's 1907 thriller, The Mystery of the Yellow Room. But Indridason reaches extraordinary psychological depths. "A sad tale's best for winter," said little Maximilian in The Winter's Tale. Indeed, but this outstanding specimen is a good one for late-summer reading too.