This novel marks the third outing for Dr Siri Paiboun, the septuagenarian protagonist of Colin Cotterill's genre-defying series set in Laos.

It is 1977, two years after the Pathet Lao declared victory over capitalism, banished the country's monarchy and ushered in a socialist republic in one fell swoop.

For Siri, the transition between the feudal slavery of the ancient regime and the freedoms of a Marxist-Leninist society has brought more than one sobering surprise.

After years spent rotting in the jungle with his comrades as the US dumped millions of tonnes of ordnance on their heads, he believed victory would bring retirement with it, not a new job as national coroner.

Further, the man of science and dialectical analysis is not best pleased to find that his battered body is the corporeal vessel for the millennia-old spirit of the great Hmong shaman, Yeh Ming.

Rather than resting his weary bones the good doctor is instead rattled between the gnarly realities of his corpse-ridden day job and the downright freakiness of the netherworld and the evil phibob spirits. This schizophrenic battle between rationality and mysticism, plus his finely honed sarcasm, cynicism and fervent distaste for party apparatchiks, sets the book's narrative pace and tone.The book begins with Siri and Dtui, his nurse, holed up in Guesthouse Number One near the Huaphan Caves, the Pathet Lao's wartime headquarters. An ossified corpse is exposed in a concrete pathway near the caves and the coroner is set the task of working out who it is before the imminent inauguration of the caves as a national monument.

He is stonewalled when he discovers it was a Cuban nurse on loan to Laos, who was seemingly involved in a soul-swapping voodoo love triangle with another Cuban and a Vietnamese officer's daughter; they are also missing.

With typical respect for Lao bureaucracy Siri digs deeper, developing a newfound love of pop music that ends with his grooving at a midnight rave for ghosts: the eponymous departed in the caves. Closer contact with the spirits aids his inquiries, enabling him to expose the murderous intrigue and to catch the killer.

Cotterill brings a sense of authentic everyday life to the fore throughout Disco for the Departed. His descriptions of mundane and incidental goings-on are as important as the bigger picture in bringing the pages to life. The rivalry between Laos and Thailand, internecine government battles, Vietnamese interference and general sending up are all set within a relevant cultural context. The rendering of the spirit world rings equally true.

Cotterill is a master of the oddball and the general goofiness of the book is delivered with precision, creating laugh-aloud moments. Characters are well formed and human, prominent in their own right rather than being mere props.

There is a tried and tested formula at work throughout the book and the rest of the series, which is at times a little too obvious. Siri always has at least one real-world case to solve. He inevitably becomes involved with the spirits, which often involves a battle with the phibob, and unconnected events regularly converge at the climaxes.

But the stark originality of the plot, its characters and the overall setting convincingly win through. Disco for the Departed is best taken on its own merits: as an off-the-wall black comedy that sheds light on Southeast Asia's least-known nation and exposes something of the human condition.