Fifty years after its posthumous publication, Flann O’Brien’s The Third Policeman remains both wildly funny and deeply unsettling. The novel’s genius (in both senses, characteristic quality and brilliance) is to use comedy not as relief from the uncanny but to create it. Something the unnamed narrator says might be applied to the work as a whole: “What he was doing was no longer wonderful but terrible.”

The final scenes reveal that the narrator is not in fact in the Irish countryside, where the book appears to take place, but is dead and in hell, though unaware of either fact. His first words make it clear why he’s there: “Not everybody knows how I killed old Phillip Mathers, smashing his jaw in with my spade.”

The novel’s genius is to use comedy not as relief from the uncanny but to create it.

“Not everybody knows” is how one begins a boast, not an act of contrition. The words tilt askew as he continues: “but first it is better to speak of my friendship with John Divney because it was he who knocked old Mathers down by giving him a great blow in the neck with a special bicycle-pump which he manufactured himself out of a hollow iron bar.” The denotations are accurate enough but the connotations are oddly off. The pump is not “made” by Divney, a manager of the narrator’s family farm, but “manufactured,” and not from a “pipe” but from a “hollow iron bar.”