"Prophecy" is essentially an indoctrination course in liberal guilt, shabbily disguised as a monster melodrama. Indeed, it's such a motley monster picture that it may be lucky to attract fleeting snickers as a kind of poor man's "Alien."

It's poignant to recall that David Seltzer's dreary, sanctimonious material was being treated like a state secret while the film was in production. The practical effect of the secrecy has been to prevent the filmmakers from hearing skeptical evaluations that might have prevented them from prat-falling onto the screen with a ludicrous polemical horror story.

"Prophecy" takes the Minamata mercury poisoning disaster in Japan and crosses it awkwardly with horror prototypes like "The Creature from the Black Lagoon" and "The Legend of Boggy Creek."

Robert Foxworth plays a doctor employed by the U.S. Public Health Service in Washington, D.C. In his opening scene he treats a ghetto infant for ratbite, expresses righteous anger at the landlord and laments his inability to make much headway against all the injustice and suffering in the world. It might have saved time to tattoo the phrase "Man of Conscience" on his forehead.

Curiously, this virtuous healer has a cellist wife, Talia Shire, who is afraid to tell him she's pregnant, lest he rebuke her with his standard lecture on the sin of bringing children into a world already teeming with starving children.

Shire decides to brood a little longer before taking Foxworth into her confidence, leading you to surmise that he's not only an opinionated jerk but also a petty tyrant. Although we're meant to feel that these people possess exquisite sensibilities, it's more reasonable to jump to the conclusion that theirs is a grotesque marriage. Nothing happens to contradict that first impression.

Foxworth is offered a chance to switch over to EPA and do an evironmental study on a woodland area of Maine where some local Indian tribes are at odds with a lumber company.When the job is offered and accepted, it appears to be taken for granted that the lumber company is despoiling the environment, a suspicion that the screenwriter speedily confirms.

Before they can even settle into a rustic lakeside cabin, Foxworth and Shire witness an Ugly Scene. The Indians, led by an adamant pose-striker in the person of Armand Assante, have blockaded a road. The lumber company manager, Richard Dysart, orders one of his lumberjacks to clear the way Assante pulls a hatchet.

Following one of the silliest duels ever filmed, the lumberjack's chainsaw prevails over the militant's ax. Assante ends up on the ground, a buzzing chainsaw at his throat, but his eyes continue to reflect indomitable defiance.

After a supper of fresh fish from a lake ominously teeming with big ones, Foxworth excuses himself to answer a scratch at the door. It turns out to be a crazed raccoon, which barges inside and threatens to rip up the inhabitants before Foxworth overpowers it.

This bad omen soon leads to others.

Assante approaches Foxworth and tells him that something has been poisoning the tribespeople. The area has been plagued by strange deaths and disappearances. An autospy on the brain of the raccoon confirms Foxworth's hypothesis: methyl mercury contamination, originating from somewhere in the lumber mill.

Now Shire has a new apprehension her unborn child might be deformed. The fauna of the region have begun to mutate hideously, and there's a prize mutant, a monstrous wormy creature with a pig's snout and the disposition of an irritable grizzly bear.

The humans, exhibiting supreme stupidity, contrive to provoke the monster by finding and appropriating a pair of its young. Foxworth is determined to transport them back to civilization in order to prove how nature has been mucked over.

The public health and moral issues raised by cases like Minamata are not clarified or enhanced by such oafish moviemaking. "Prophecy" is an embarrassment among horror movies, not to mention an inadequate pretext for social criticism.

The problem must originate in the presumption of piously liberal film-makers. They expect to be excused every absurdity, cliche and shortcut as long as we're all agreed that their hearts are in the right place. "Prophecy" demonstrates how this self-righteousness leads them to mangle or poison every issue they try to call attention to.