Desperate times demand desperate measures, and New York is in dire straits: Its children are being struck down by a ruthless plague that's carried by the ubiquitous cockroach and for which there is no cure. Recruited by a desperate doctor from the Centers for Disease Control (Jeremy Northam), clever entomologist Susan Tyler (Mira Sorvino) comes up with a radical and icky solution, genetically engineering a sterile, self-destructing super-roach that mingles with its scuttling brethren and poisons them dead. The Judas Breed she calls it, laying on the irony as only a brainy academic can. But three years after her audacious triumph, odd things are afoot. A mutated carcass in the sewers. Strange figures lurking in the shadows. Fringe dwellers vanishing without a trace. And a Judas bug found deep in the bowels of the subway system, two-and-a-half years after the last of them should have gone belly up.

Told in the darkly dreamy style of a particularly grim fairy tale, the creepy, beautifully designed Mimic embraces the clichs of the big-bug story-scientific hubris and the inevitable revenge of nature-and makes them seem, if not fresh, then certainly as robustly vital as the oversized vermin that stalk its pervasive shadows. Mimic also has an unusually high yuck factor, involving all manner of sticky, slippery, squishy things, but to call it a gross-out movie would be, well, grossly inaccurate. Making his U.S. debut, Mexican director Guillermo Del Toro (Cronos) rejects the adrenaline-charged, roller-coaster ride approach that drives so many recent thrillers in favor of constructing a densely imagined nightmare of damp streets and nightmare alleys.

Del Toro's distinctly European sensibilities are perfectly attuned to the demands of a nightmarish fairy-tale, simultaneously sentimental and cruel. Horror hard-liners will probably cry 'wimp' at the sequences involving elderly Manny (Giancarlo Giannini), who has a shoeshine stand in the subway, and his angelically remote grandson (Alexander Goodwin), who twists wire into weird figurines and imitates sounds with spoons. But be warned: Just because Del Toro is sentimental about children doesn't mean he's squeamish. And once our cast is trapped in an abandoned subway car deep beneath the city streets, Del Toro proves that he doesn't just have a way with the poetic stuff: He can construct a nail-biter with the best of them. In all, Mimic is proof positive that his haunting, offbeat vampire tale, Cronos, wasn't a fluke, and should signal the start of a major U.S. genre career.

--Maitland McDonagh