Actually, Prophecy isn't a bad movie, it just isn't a very scary one. There are strong performances by Richard Dysart and Armand Assante (who, improbably, plays a Native American), and genuine dramatic tension between the loggers and Indian activists the two actors represent. The drama is heightened when members of both groups, who strongly distrust each other, are forced to rely on each other to survive. Although the film's environmental theme is unmistakable, it doesn't make the Dysart's character, the head logger, a caricature. Frankenheimer was obviously right at home directing the more political aspects of this "thriller," and the film would have been stronger had he stayed in that territory, because as a horror film it frequently falls flat.
The film is rife with weaknesses, including unconvincing special effects (remember the exploding sleeping bag?) and wooden lead characters. Star Robert Foxworth, an inner-city doctor sent from New York City to mediate the logging dispute (huh?) because "people relate to him" (huh?) almost immediately sympathizes with the Indians and proves generally skeptical, combative and condescending, and co-star Talia Shire delivers a nigh-comatose, Judith O'Dea-style performance.
// spoiler alert //
It also contains one of the most egregious examples of what Ken at Jabootu's Bad Movie Dimension would call the Hero's Battle Death Exemption: despite the fact that the mutant bear is consistently shown to kill with a single blow, Foxworth's character is able to survive combat with it long enough to stab it to death with an arrow. Indeed, Ken uses this very movie as the example to define the term.
Watching it last Halloween, I told my wife (the fact that we were watching it together should tell you how non-scary it was) that rather than running with the mutant bear angle, the film would have benefited from a Scooby-Doo ending: having the "mutant bear" wind up being a hoax perpetrated by either the loggers or the Indians to scare the other side out of the forest. That would have capitalized on Frankenheimer's strengths in directing a politically concious thriller, and made the "surprise" appearance of another mutant bear at the film's closing much more shocking.
Shoot...I didn't really mean to make this obit of Frankenheimer into a rant against one of his lesser offerings. He was a fine director, and The Manchurian Candidate is one of my favorite films. Check it out some time.