The space that science fiction inhabits is strung between the here-and-now and the elsewheres in which it is located. So the quickest way to generate that elusive sense-of-wonder is to go for distance and scale: take the reader thousands of years into the future, and set the tale in a galaxy far, far away. Yet, as J G Ballard has reminded us, the only truly alien planet is ours; and the most challenging future is the one 15 minutes away. Jeff Noon, in Nymphomation (Doubleday, pounds 15.99), and Ian Watson, in Oracle (Gollancz, pounds 15.99), snatch up the Ballardian gauntlet in novels which place their final frontiers just around the corner.

Noon returns us to the trip-hopped Manchester of his ground-breaking diptych, Vurt and Pollen. Often compared to William Gibson, Noon reveals that they have very different tastes and takes. Gibson draws on Burroughs for a laconic, demotic style; Noon mines him for surreal delirium. Gibson taps Ballard for glacial calm; Noon gulps thirstily at Ballard's subterranean lyricism.

Nymphomation is an exquisitely grimy fable which plunges us into a world of club culture, smart drugs, dumb waiters, artificial life-forms designed solely to carry advertising and a national lottery from hell. Noon rides both his prose and his ideas right to the end of the line, with a surgically pitiless eye for cultural faultlines and a compassionate empathy for the civilians caught in them. The result is an imaginative and linguistic tour de force. If the cover doesn't glow under ultraviolet light, it should.

Ian Watson's 31st book hinges on one whopper of a coincidence, which requires a more strenuous suspension of disbelief than its central SF device. A British espionage-technology gadget accidentally opens a time- window into the distant past. It snatches up a Roman centurion on his way to assassinate Queen Boadicea and deposits him in our own time, smack on the A5. No problem. However, the notion that the guy who finds him should not only be a fluent Latin speaker but also have a sister who is the former lover of an IRA triggerman takes some heavy swallowing.

This Olympic-level act of ingestion duly accomplished, we're into a political thriller which moves like paranoid lightning over some tricky terrain. The nature of fame; the demands of national security; the ethics of the media; the theory and practice of terrorism: all are stressed until they crack open, but Watson never neglects the thriller priorities of plot and character. Oracle is a miniaturised blockbuster with brains: a kind of Prince Naseem beside the lumbering Tysons of the techno-thriller division.

Meanwhile, the ever-resourceful Paul McAuley is doing something else entirely. Pathologically reluctant to repeat himself, he has delivered distinctive variations on any number of standard SF themes, and Child Of The River (Gollancz, pounds 16.99) is no letdown. McAuley drily upends a couple of classic riffs: the mysterious baby-from-nowhere who arrives, Moses-like, into an unsuspecting community; and the once-technological society which has slipped backwards into medieval mores. This is the first book of a trilogy, Confluence, which looks set both to inject a welcome dose of sophistication into the clumsy genre of science-fantasy, and to attract readers who normally wouldn't touch it with the proverbial bargepole.