Jonathan Lethem’s much-anticipated new novel is set in Manhattan in a year that is a hybrid of 2004 and some future date. Marlon Brando has just been reported dead, but the New York Times publishes a war-free edition and the Chinese have sowed deadly mines in outer space. A grey fog envelops the financial district and a Christo-like artist creates gaping “urban fjords” throughout the city, into which citizens occasionally plummet. Most perilously, an escaped tiger (which may, in fact, be an amok subway-tunnelling machine) is rumoured to be behind a series of cataclysmic events around the island.

Populating this surreal landscape is a collection of characters with larger-than-life names — Perkus Tooth, Richard Abneg, Chase Insteadman, Georgina Hawkmanaji, Laird Noteless. Despite these scenery-chewing appellations, however, Lethem’s cast remain decidedly spectral, often overshadowed by the looming skyline of the novel they inhabit.

Take Insteadman, the book’s narrator. A simple description suggests a fully fleshed character capable of commanding the reader’s interest and sympathy. A former teen-television star now ­living comfortably on residuals from his one-hit show, he is back in the media ­spotlight because his fiancée, an astronaut named Janice Trumbull, is trapped in outer space. Her heartfelt letters to him are printed in the tabloids, earning him the sympathy of this most hard-hearted of cities. Trying to get on with his life, Insteadman befriends the hard-to-like Tooth, a pamphleteer and music critic who lives in marijuana-shrouded isolation, and Abneg, a former housing crusader who works for the city’s billionaire mayor. He also conducts an impulsive, guilt-inducing love affair with a sexy ghostwriter named Oona, who may be more implicated in his life than he knows.

Despite these numerous facets, Insteadman remains two-dimensional. He is so rigidly a vehicle for the author’s various thematic ­concerns that it is difficult to find him credible as a human being. Perhaps this is the point. Chronic City is above all a novel that sets out to map the fuzzy terrain between the real and the virtual, the “ersatz and actual”. However, this agenda often leaves the reader confused as to where he stands.

Lethem moves his large cast through his futuristic terrain like a tech wizard blueprinting a complex video game. In fact, it comes as little surprise that a role-playing game called Yet Another World plays a significant part. This involves several of the characters searching for a seductively beautiful urn that one of them spots in an alternative-healer’s office. Occasionally it seems that Lethem’s Manhattan is nothing more than a sweaty, turbulent simulation. One character even suggests the city may have been created by a giant computer, and that they are all just “little simulated beings…who sincerely believe they’re truly alive”.

At times, Lethem’s narrative takes on a panoramic majesty, especially when it focuses on the crumbling city. At one point, he perfectly evokes what lies beneath the erupting pavements, where “lines of television cable and fresh water and steam heat and outgoing sewage and telephone wire and whatever else…cohabit in the same intestinal holes that pavement-demolishing workmen periodically wrench open to the daylight and to our passing, disturbed glances”.

The occasional power of Lethem’s prose fails, though, to pave over the poorly connected tangle of plot and characters. It is no coincidence that the book’s most affecting character is the one most physically removed from its action — Janice, the “lostronaut”, whose rambling letters from her geosynchronous prison are oddly moving. The same cannot be said for the characters who spend more time on stage. Lethem may have set out to create a vivacious mural of a city in decay, but, in the end, he manages only to create a series of gorgeous fjords into which his people vanish.

Chronic City by Jonathan Lethem
Faber £14.99 pp480