The underdog on the 2016 Man Booker Prize shortlist was the then relatively unknown Scottish author Graeme Macrae Burnet. Although it lost out to Paul Beatty in the end, Burnet's historical crime novel about one man's "most sanguinary deeds" made him a writer to watch. For "His Bloody Project" was more than a stirring tale of murder and madness in the Scottish Highlands in the 19th century. Composed of memoir excerpts, police statements and medical reports, it was also a cleverly crafted work, one that invited the reader to sift the collated evidence and determine the reliability of the narrators.

Burnet's new novel is another formally inventive offering made up of various documents, all of which act as interwoven narrative threads. "Case Study" sees Burnet re-examining themes of reality and identity through characters and sources that may or may not tell the whole story. Once again, he opens with a preface by a writer called "GMB," who attempts to pass off the startling fiction that follows as fact.

GMB explains how he came to possess six notebooks written by a former patient of Collins Braithwaite, a radical psychotherapist from the 1960s. Braithwaite is now forgotten, discredited and disgraced and his work is out of print. GMB is fascinated by this fallen figure but also wary, in case the notebooks, which supposedly contain allegations about Braithwaite, are forgeries. Despite his reservations, GMB reads the notebooks and presents them interspersed with his own biographical research into Braithwaite.

The notebooks give an account of events from 1965 by an unnamed woman. She is convinced that Braithwaite, "Britain's most dangerous man," should bear the blame for her sister's recent suicide. In a bid to find out who he is and how he drove her sister over the edge, the woman assumes the name of Rebecca Smyth and arranges a consultation with Braithwaite at his London practice. "Suicide," she writes, "makes Miss Marples of us all. One cannot help but look for clues."

Over the course of several sessions, "Rebecca" opens up about her past while also trying to learn more about Braithwaite — a man who takes pleasure in her discomfort, like "a cat toying with a half-dead mouse." Away from her therapy, she continues to hide behind her fabricated alter ego while going on dates with an admirer called Tom. But when Braithwaite sees through her subterfuge and Tom discovers she is not who he was led to believe, the woman starts to lose her grip on reality.

Macrae's novel works on various levels. It is an elaborate, mind-bending guessing game; it is a blackly comic and quietly moving study of a nervous breakdown; and it is a captivating portrait of an egomaniac. If the notebooks depict a gripping chain of events, then the biographical sections expertly flesh out the grotesque, manipulative yet charismatic Braithwaite. Macrae has reliably delivered another work of fiendish fun.

Malcolm Forbes has written for the Times Literary Supplement, the Economist and the Wall Street Journal. He lives in Edinburgh, Scotland.

Case Study

By: Graeme Macrae Burnet.

Publisher: Biblioasis, 288 pages, $16.95.