The Troubled Man, By Henning Mankell

Inspector Morose – the depressive detective Kurt Wallander – mounts what the author says will be his final investigation

More accurately, there are two troubled men at the heart of the latest Henning Mankell novel, not one. The first is Haken von Enke, an upper-class Swede who rose quickly through the ranks to become a senior naval commander during the Cold War, until his career stalled following an incident in the early 1980s: von Enke cornered a foreign submarine in Swedish waters but, rather than force the vessel up to establish its presumed Russian identity, he allowed the submarine to escape.

In 2008, Detective Kurt Wallander's daughter Linda (with whom he has a loving but prickly relationship, exacerbated by her decision to follow him into the police force) announces that she and von Enke's financier son, Hans, are going to have a child together. Linda coaxes Wallander to join them at a party to celebrate Haken's 75th birthday, during which the retired commander corners the detective with a long account of the Cold War stand-off, and his subsequent suspicions about possible high-level espionage and a political cover-up. After 25 years, von Enke feels he is close to the truth, and seems distinctly uneasy about it.

The second troubled man is Wallander himself, who is in the region of 60, works and drinks too hard, exercises too little, is overweight, over-stressed and lies awake at night thinking of death. He's diabetic and takes a daily cocktail of seven pills, which he wisely keeps quiet from Linda – who nevertheless has an astute grasp of her father's emotional health: "loneliness will eat you up from the inside". Relations with Linda's mother remain vituperative, and a chance visit from Baiba Liepa, who spurned Wallander's offer of marriage during their passionate affair a decade earlier and is now dying of cancer, adds grief to his morbidity. Perhaps even more alarming, moments of complete mental blankness are overwhelming Wallander with increasing frequency, and terrify him so much that he hasn't the nerve to consult a doctor.

On the face of it, Mankell's plot is relatively simple. One day, Haken goes missing during his morning constitutional, leaving behind his phone, passport, money and any rationale as to his disappearance. No body, no trace. Wallander enquires, unearthing a steady stream of clues about von Enke and his wife Louise, a modest woman with East German heritage. When Louise's body is found in woodland a month later, along with classified microfilm, Wallander's drive to make sense of it all pushes The Troubled Man relentlessly on towards murky revelations of high-level treachery.

The anchor of Wallander's person-ality ensures that The Troubled Man operates as a good, gritty procedural rather than a spy thriller, but the historical context adds depth and texture to the investigation. In fact, history intrudes into much of Mankell's work. Depths plumbed an earlier wartime nautical theme but fell flat through wooden characterisation; Daniel was a 19th-century African sortie with uneven voices and a flagging pace; and The Return of the Dancing Master uncovered a Europe-wide resurgent neo-Nazism festering in rural Swedish hamlets. None of these three featured our morose detective, but Mankell's adeptness at weaving big ideas into seemingly local crimes has often given his Wallander procedurals an expansive atmosphere. Firewall very effectively conjured the plausible threat of global cyber-terrorism initiated in sleepy Ystad, Wallander's home town, while The White Lioness put KGB assassins into Sweden's misty coastal landscape, and a plot to murder Nelson Mandela and foment civil war in South Africa.

Mankell is undoubtedly a skilled writer with plenty of breadth, but it's clear that his subtleties of character, plot and pace achieve greatest expression in the Wallander series. The detective's phlegmatic personality is the binding agent. He has a mournful cast of mind (and understated fondness for opera) that isn't far removed from the very English dourness of Inspector Morse, and he seems to triumph through graft and intuition rather than forensic subtlety.

It's the lack of glamour that really anchors Wallander's insomniac, fretting demeanour; a graininess that is neatly polarised by the two screen interpretations that have boosted the Wallander brand in recent years. Kenneth Brannagh's BBC episodes were visually beautiful and engaging but a touch overplayed. The Swedish TV series starring Krister Henriksson retains Mankell's downbeat, rainy atmosphere and carries a correspondingly heavy emotional heft.

When, in this valedictory eleventh outing, Wallander hears of the death of his former lover, "he lay down on the bed and stared up at the ceiling where a patch of damp had appeared ... and could feel a sense of mounting desperation". It's this quiet inner turmoil that drives the procedurals, and that closes, with an absence of histrionics, the hugely absorbing Wallander casefile.