It's hard to overestimate the impression made by Michael Cunningham's The Hours; this was literary fiction of a rare order, detailing the inner lives of its female protagonists with sympathy and understanding. Now we have Specimen Days, and this has to be counted among the most eagerly anticipated novels in recent years, such is the reputation of the Pulitzer prize-winning novelist has acquired in a relatively short time. And if Specimen Days does not immediately exert the grip of its predecessor, this is due to no failure of technique. Cunningham knows exactly what he is doing, and his slow, penetrating accretion of detail ultimately pays off in ways that are richly satisfying.

The various sections of the novel describe the same group of protagonists: a young boy, a young woman and an older man. But the treatment of these characters is strikingly varied from section to section, and the ambitions of the novel are jaw dropping. In the Machine is set during the industrial revolution, and balances the carefully examined pathology of its characters against supernatural elements. We are then taken to the early 21st century in The Children's Crusade which has a far grittier tone, with a terrorist group setting off bombs at random throughout the city. Finally, we are plunged 150 years into the future, when the city of New York is struggling to deal with the host of refugees from a planet that astronauts have reached.

All of these widely disparate narratives are united by the telling presence of the poet Walt Whitman, who acts as an anchor for the reader in a narrative that disorients as much as it stimulates. Not everyone will be able to accept the massive reach of Cunningham's novel, and the wrench between different time periods is certainly more shocking than that in The Hours. But for those willing to accept the new and challenging, Specimen Days is a masterful and visceral read. --Barry Forshaw