Eight-minute prologue illustrates a terrible epidemic in Manhattan that afflicts many children but is eradicated by a gifted young scientist, Susan Tyler (Sorvino), when she introduces a new breed of insect into the city to eliminate the conventional cockroaches that she has determined are carrying the plague.
Three years later, however, the roaches come home to roost. First, a specimen of her specially engineered Judas breed, long since suspected to have died out, turns up, followed by egg pods. Various unsuspecting human victims are gobbled up by the hungry, hard-shelled predators, which have the uncanny ability to transform themselves into human-like form when necessary, following the logic that numerous creatures in the animal kingdom over the millennia have managed to adapt themselves physically in order to survive.
Leaving aside the question of how many species have ever evolved so dramatically within three years’ time, Susan gets her hands on a particularly disgusting roach corpse for dissection purposes and, with the help of her mentor (F. Murray Abraham), determines that there is a colony of the ugly critters about.
Pic still seems to hold the promise of some good scares, if nothing else, when Susan is snatched by a creature, which transforms itself from humanoid to giant flying critter for the occasion, and is carried off into a tunnel, to be deposited in a roach nest.
Remainder of the picture is mostly set in the dingy bowels of the subway, as Susan manages to escape and joins her scientist husband (Jeremy Northam), a fellow worker (Josh Brolin) and cop (Charles S. Dutton) in an abandoned subway car to concoct desperately a scheme for turning the tables on the angry, lip-smacking beasts.
Along the way, a fair number of humans, including some kids, get devoured, although it never becomes clear why so much screen time is devoted to the perplexing activities of an aging shoeshine man (Giancarlo Giannini) and his grandson (Alexander Goodwin), the latter of whom seems to have a special affinity for the roaches.
Unfortunately for a film in which a very limited number of characters become imperiled together, pic devotes no attention whatever to characterization, so they are all just pieces of meat that may or may not get eaten. Even Sorvino, an unusually intelligent and graceful participant in such a genre item, eventually gets reduced to standard alternations of scared and brave gestures, and is asked to bring precious little of her previously demonstrated talent to bear on the proceedings.
Del Toro clearly knows his way around the camera, but the shadowy eeriness that saturates the early going slowly becomes monotonous and winds up being just dull, and even partially obscures the action in the long underground finale. Gloomy tone could usefully have been leavened with humor, but the only laughs are unintentional ones.
Special insect effects are accomplished enough, if disappointingly fleeting. A number of scenes produce the sought-after gross-out result, which will provide sensation-seeking genre fans with at least a measure of what they desire. But the direction goes for pure shock rather than artfully built surprise or suspense, cheapening its cumulative impact and leaving it far short of the models of the first two “Alien” films, to which it clearly aspires.