Rob has spent most of his confusing adult life wandering, writing, and imbibing literature and narcotics in equally vast doses. Now, stranded between reckless youth and middle age, between exaltation and despair, his travels have acquired a de facto purpose: the immemorial quest for transcendent meaning.

On a lurid pilgrimage for cheap thrills and universal truth, Doyle's narrator takes us from the menacing peripheries of Paris to the drug-fuelled clubland of Berlin, from art festivals to sun-kissed islands, through metaphysical awakenings in Asia and the brink of destruction in Europe, into the shattering revelations brought on by the psychedelic DMT.

A dazzling, intimate, and profound celebration of art and ageing, sex and desire, the limits of thought and the extremes of sensation, Threshold confirms Doyle as one of the most original writers in contemporary literature.