In Prey, Michael Crichton finally builds one of his science thrillers around a technical innovation to which he has paid far too little attention in the past, one that's tailor-made for his gifts as a storyteller and that immediately lifts his crackling new book above ''Timeline,'' ''Airframe,'' ''The Lost World,'' and even ''Jurassic Park.'' Laymen call this handy invention the first-person narrator.
For a writer like Crichton, whose prose usually trudges forward like a water buffalo while his plots zip along like stampeding wildebeests, first person makes all the difference. Here, it serves the story by allowing Crichton to pass his own stiffness on to Jack Forman, his 40-year-old protagonist. The uptight, gawky voice suits Jack, a laid-off Silicon Valley programmer with reason to be uneasy, as the beginning of the book finds him trying to adapt to life as a househusband: burping the baby, making spaghetti, reading Redbook, and tiptoeing around his moody workaholic wife, Julia.
It's her dark dealings in the science of teeny-tiny robots, or nanotechnology, that drive Crichton's novel, and with Jack shepherding the story along more fleetly than any omniscient Crichton narrator ever has, ''Prey'' gets going awfully fast. Julia is part of a team trying to develop a swarm of camera-equipped, submicroscopic ''nanobots'' that would lead a revolution in medicine. Just as she's making breakthroughs, she begins behaving erratically, like someone who might be on drugs, or having an affair, or plotting a divorce -- Jack can't tell. Worse, one night the baby breaks out in an excruciating rash that, as Jack watches, spreads over her entire body in one swoop. Because ''Prey'' is one more Crichton novel in which good science goes bad, the smart oddsmaker would blame the nanobots, not Jack's homemaking skills, for all of this.
These opening pages -- tense, mysterious, subtle -- are among the best Crichton has ever written; they end as Julia is waylaid by a strange plot twist and Jack is called to the isolated nanotech lab in the burning Nevada desert. There, he quickly learns not only that the nanobots have been co-opted for shady purposes by greedy scientists but also that a black swarm of little baddies has escaped into the desert and is evolving quite nicely into an optimum killing machine all by itself. The ''mechanical plague'' must be stopped. Updated for the new century, the old stranded-at-the-outpost, cat-and-mouse plot ensues.
For the rest of the book, Crichton operates on roller-coaster mode, which is disappointing considering his effective start. Concocting sweaty, boffo action set pieces is the author's forte, though, and he dashes them off at such a clip that even genre staples like the dirt-bike escape scene or the bit where the good guys are trapped by the evildoers inside the car are still mighty entertaining. And in his characters' downtime, Crichton runs us through the science again and again, but never superfluously. He smoothly integrates quick, lucid discourses on a number of subjects (computer programming, animal behavior, and evolution) that illuminate the plot mechanics and do a pretty good job of educating the ignorant.
Meanwhile, something is evolving toward truly hideous dimensions, and readers will be shocked to discover what that something is: Crichton's increasingly bombastic action scenarios. All told, it's a pretty big buzzkill when the last 100 pages of Crichton's most polished read find him up to his lazy old tricks. He just can't resist the showman's ambition to make everything bigger, goofier, and more cinematic. (Film rights, of course, have already been snapped up by Fox for $5 million.) Since his books warn against milking good ideas to their bitter ends, why, for instance, is he compelled to keep evolving his black swarm into an impossibly all-powerful foe, seemingly capable of any desert villainy short of catching the Road Runner or opening its own Starbucks? This is especially annoying because his supporting cast, the usual bag of faceless whiz kids unimaginatively offered up one by one as surprise bad guys or sacrificial lambs, could have used the extra attention.
Poor Jack gets a little lost in all the hoopla too; even he can't make much of the finale, insisting after a particularly garish plot twist that he's ''badly worried'' when in fact he'd be justified, given what he's just learned, in blowing his brains out. That would have been an ending, a bumped-off first-person narrator. But ''Prey'' blazes enough trails that no one will mind that none of them are literary.