Three of Thomas Pynchon’s five previous novels are lengthy, historical and set in worlds about to explode. His 1963 debut, V. (full of panicky, paranoid types yelping “the balloon is going up!”), depicts a series of crises between 1898 and 1956 for the dying British empire; Gravity’s Rainbow takes place in England and Germany in the final phase of the second world war, just before Hiroshima; and Mason & Dixon in the 1760s in a colonial America soon to fight a war of liberation.

His sixth, the gigantic Against the Day, continues the pre- apocalyptic pattern. Revisiting an era that fascinated the author in V., it largely unfolds in the years leading up to the first world war, opening with the Chicago World Fair of 1893. The multistranded plot involves a typically motley cast of travellers, spies, mathematicians, revolutionaries, mystics, engineers, femmes fatales, entrepreneurs, sleuths, actors, saboteurs, entertainers and sexual avant- gardists; and the novel teems with countries as well as characters, in addition to taking in half the nations of pre-1919 Europe.

Pynchon’s fiction has been compared with Melville’s and Joyce’s in its “encyclopedic” ambitions, and here he seems more intent than ever on squeezing in everything significant from his chosen period. It is an idiosyncratic compendium, however, in which textbook history is all but ignored in favour of forgotten wars or workers’ struggles, obscure culs-de-sac in science, overlooked thinkers and daft, ephemeral social trends.

What also differentiates it from a conventional encyclopedia is that most of the material is given a comic twist. It happily features signature Pynchon ploys such as musical numbers, funny names (Rev Lube Carnal, Prof Heino Vanderjuice, Lord Overlunch) and intelligent animals, and displays his outstanding gift for spoofs and zany inventions. I particularly liked the operetta The Burgher King (about a comfort-loving monarch who disguises himself as middle-class).

The novel actually begins in pastiche mode, brilliantly mimicking Victorian wordiness as it introduces us to the Chums of Chance, a band of adventurers who tour the world in a balloon, dropping in on events such as the fair when not acting as crisis troubleshooters. A joky version of the earnest explorers in the science fiction of Jules Verne and Arthur Conan Doyle, they reappear regularly and set the dominant tone of brainy playfulness.

One American family provides several other leading characters. Webb Traverse is a mining engineer whose campaign to sabotage ruthlessly run mines in Colorado results in his murder. Of his three sons, two (Kit and Reef) migrate to Europe, while the third finds work in revolutionary Mexico; determined to avenge their father’s death, they are appalled when their sister marries one of the killers.

Also prominent are Yashmeen Halfcourt, an exotic Cambridge graduate associated with TWIT (a London-based organisation combining mysticism with espionage) who has affairs with Kit and Reef; Lew Basnight, a private detective hired by TWIT and involved in its search for a Shangri-La; Scarsdale Vibe, an evil, deranged tycoon with whom Kit signs a Faustian pact that he comes to regret; and Merle Rideout, a photographer and technician whose daughter Dally becomes first an actress in New York, then an artist’s muse in Venice, where she falls for Kit.

Sheer amazement is the main response the novel elicits. Pynchon’s enthralling ambitiousness and phenomenal imaginative power remain undiminished. But his ability to create stories that grip seems reduced: there’s a weightlessness to the characters that makes them hard to care about, and the point of the proliferating narratives is often elusive, particularly in the Europe-dominated second half — as much as 300 pages could be cut without obvious loss.

And something else is missing. His novels since the 17-year silence in the 1970s and 1980s that followed Gravity’s Rainbow are both more and less accessible than the ones before it: less because they present formidable challenges to the reader (Mason & Dixon is written in 18th-century language, Against the Day is 1,100 pages), more because they’re lighter in mood. As Vibe is merely a panto villain, his latest work contains nobody comparable to the demonic characters in the early phase, such as the woman spy V. or the Nazi Captain Blicero in Gravity’s Rainbow; and its deficiencies suggest that these monsters were vital to shaping the novels as well as informing their atmosphere of paranoia. Against the Day resembles Moby Dick in its vast scale, its displays of learning, its engaging larkiness. But it’s a Moby Dick with no Ahab, and no whale.

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