Miss Marple in a cassock

The antiquity of the Vatican, the nuns seen-but-notheard, the aged, all-male college of cardinals, the robes, the incense – St Peter’s has always had the air of a faintly sorcerous retirement home. This whiff of the arcane and the absurd hangs particularly pungent over the process of papal conclave, when the elderly cardinals are hustled into the Sistine Chapel for politicking sequestration, black puffs of smoke announcing their continued captivity, pure white the elevation of one of their number.

This all feels more like the territory of Dan Brown’s

distinguished Harvard symbologist Robert Langdon (currently befouling a cinema near you) than one of Robert Harris’s more taciturn heroes. But Harris has a quiet flair for theatricality, and delights in B-movie tropes such as malevolent super computers ( The Fear Index) or volcanic conflagration ( Pompeii). In the hands of a less skilled practitioner, Conclave, a twisty romp stuffed with corruption and cassocks, might have fallen apart, but in fact it’s a triumph. Harris turns the papal election into an unusual locked-room mystery.

Our hero is Cardinal Lomeli, a mildly ossified septuagenarian; very much a prince of the church, swathed in carmine; a technocrat, wracked by doubt. Harris’s best protagonists have always been insiders compelled by their better angels to impose themselves on history. Picquart, in An Officer and a Spy, was a supercilious snob infected with the same anti-Semitic feeling against which he strove; Cicero, in the trilogy that began with Imperium, was an appallingly

pompous bore, but intensely human and undoubtedly great. Lomeli is cut from the same cloth – also conflicted, also relatable.

His role as Dean in the election demands impartiality but before our cardinals have even begun their seclusion, Lomeli is snooping around like Miss Marple in a funnier hat. He is shocked to be accused of Machiavellianism by a fellow cardinal, but as Lomeli discovers more corruption, malfeasance and sin, both he and the reader must confront the waxing ambition behind his actions. Our noble prelate has feet of clay – and is all the better for it.

Where Harris is tremendous is in scaling the mountains of exposition his tale requires. Initially, the reader is assaulted with curial titles, but once the vast mass of papal bureaucracy has been indicated, Harris prunes the jargon back to the bare essentials.