The problem I had with The Mothman Prophecies is that it, well, predicts itself throughout the movie. Even if you don't know the details of the actual story it is based upon, the film is about some outside force telling the main characters what they can expect next, and despite all their efforts to the contrary there is next-to-nothing that they can do about it. It has some scary moments, but nothing really shocking. The movie flirts with the line between a skeptical interpretation of events and the fantastic; thus neither direction is given its due and the film ends up being mediocre.
John Klein (Richard Gere) is a DC reporter who's wife is involved in an auto accident after she tried to avoid something in the road. During her examination for a head-injury, it is determined that she has an inoperable brain-tumor and she dies. Klein discovers a number of sketches she did of what she thought she was trying to avoid the night of her accident, a strange, black, winged creature.
2 years later, Klein gets lost while traveling and finds himself in Pointe Pleasant, VA. He discovers that the townspeople are being afflicted by a variety of weird phenomenon; weird lights in the sky, strange phone calls, and encounters with the "Mothman", a creature similar in description to his wife's drawings. Klein discovers that the appearance of the creature often foretells disaster. Things get only more intense as he becomes obsessed with the creature and begin receiving calls from a malevolent entity calling itself "Indrid Cold". Cold makes predictions and warns Klein about an ambiguous danger to the town. Klein then races to prevent this unknown disaster.
The issue with this film is entirely with the story. The direction and cinematography is great, and the actors are convincing. The story itself just seems to ramble along with no real direction. You are better off reading the book or book on the subject for a little thrill than watching this film.