Stephen King writes good books. Unfortunately, those books aren’t always turned into good movies.

“Dreamcatcher,” the latest movie adaptation of a novel from accomplished horror writer King, follows four men who share a common past and psychic ability. They are especially united through their friendship with a mentally disabled man named Duddits.

The men, Jonesy (Damian Lewis), Pete (Timothy Olyphant), Henry (Thomas Jane) and Beaver (Jason Lee), travel to a cabin in the winter for some good ol’ times of hunting and beer, but the discovery of a lost man with a strange, red blotch is only the beginning of a camping trip from hell.

Aliens have come to the woods of Maine, bringing killer worms (pleasantly called sh** weasels) and moss-like blood that grows faster than any moss I’ve ever seen. The situation is further complicated by a quarantine of the area imposed by mad Colonel Curtis (Morgan Freeman playing a role that seems stale).

Somehow Duddits, dying of leukemia, seems to be the key to the world’s salvation.

Four major deaths in the first 40 minutes made me worry no one would be left by the end of the two-hour film. Horror movies have a way of killing off the best characters too soon.

For some reason, “Dreamcatcher” becomes a mess larger than the living blood that threatens to envelop the world.

Maybe it is the slimy worm emerging form the anus of a flatulent man.

Maybe it is Donnie Wahlberg, formerly of New Kids on the Block, as the unrecognizable Duddits.

Maybe it is the maniacal English accent suddenly developed by a man whose body harbors an alien.

Despite all these faults, it is still mostly an engaging ride, better than the average horror film. Stephen King, although not at his absolute best with “Dreamcatcher,” still is the best writer in his genre.

Although director and producer Lawrence Kasdan works hard on this big-budget film, his vision is unclear. He tries to incorporate into “Dreamcatcher” straight scares, eye-rolling revulsion, heartfelt tenderness, military drama, apocalyptic suspense and tongue-in-cheek humor.

At times this works, but “Dreamcatcher’s” true downfall is its unconvincing ending that destroys the small aura of mystery surrounding Duddits, who is at the center of the film’s most interesting storyline. In the end, “Dreamcatcher” fails to haul in the big fish.