COMEDIANS, WE ARE told, always wants to play Hamlet. But sometimes Shakespearean actors like to let their hair down too. It is tempting to see this as what Greg Bear, master of the sweeping science fiction epic, has done with Quantico.

Even the title makes a statement. Despite its exotic sound and origin — from an old Indian word meaning “place of dancing” — the little town on the Potomac has long been synonymous with the FBI. But it hardly has the same apocalyptic ring as Forge of God, Eon or Darwin’s Children, the titles of Bear’s previous sci-fi mega-sellers.

In a career move not unlike Bob Dylan’s decision to go electric in 1965 and which may, too, dismay legions of hardcore fans before winning new ones, Bear has dropped the galactic viewpoint to write a purely terrestrial thriller.

The blurb for Quantico proudly declares that, in 2000, the author lectured the FBI academy there on the future of crime and criminal justice. Whether he foresaw the World Trade Centre attacks or the anthrax letters sent throughout the US mail in the weeks that followed is not mentioned, but the latter lie at the scientific heart of this book.

We are in the near future — a landscape definitively outlined by William Gibson — when not just 9/11 but an ill-defined 10/4 have inscribed themselves on the US consciousness. Iraq is still in chaos but focus has shifted to Iran amid fears of a pre-emptive Israeli nuclear strike. Bear throws together isolated incidents — prototype biological weapons deals in Guatemala and Iraq, a murdered highway patrolman and an overturned truck full of inkjet printers, an FBI stakeout of a white supremacist in Washington state and his rookie son’s progress through Quantico.

Somewhat tortuously, these plot elements knit together to reveal the warped semi-autistic genius behind the so-called “Amerithrax” attacks used as a pawn by sinister forces to develop a genetically-linked anthrax deadly only to certain racial groups.

There is no scientific basis for believing in a genetic differentiator between Semitic Jews and Arabs but the FBI suspects that your average terrorist might not know that, or that Northwest Nazis are happy to kill both non-Aryan, non-Christian groups.

At the heart of the conspiracy is a mysterious man with untraceable DNA and one green eye and one blue — why he doesn’t wear a single contact lens to disguise this dead give-away is beyond me.

The climax is apocalyptic enough with a showdown in Mecca during haj, smart bombs and “sniffer” probes that detect individuals by their diet the way that dogs recognise one another by sniffing their rear ends. It's hard to avoid feeling that coming down to earth has made the Great Bear lose the scent.

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