The Crazies is rare in the horror genre in that most of the main characters act honorably and intelligently. David (Timothy Olyphant) and Russell (Joe Anderson) - the sheriff and his deputy - act quickly when they perceive a disturbing trend. A man brings a gun to a Little League baseball game and a father murders his wife and child. Something is wrong about the cold nature of the acts. When David and Russell find a downed military aircraft in the town’s water source out in the woods, they quickly see the problem and ask the mayor (John Aylward, of ER fame) to turn off the supply. Something is turning people into killers and it’s progressing into town in the same direction that the water flows. The mayor declines, which is obviously the mistake that dooms the town. Denied, the duo acts with foresight and turns it off anyway.
They’re moving quickly to quell the threat when the first of two big twists hits. The military sneaks into town to quarantine the ill and evacuate the well. For now the military are the bad guys, having heavy-handedly separated David from his pregnant wife, Judy (Radha Mitchell). David and the increasingly clutch Russell sneak back into town. But now they have to fight the monsters and the authorities.
By the time they get close to escaping they encounter the second big twist: they didn’t make such a bad decision going back into town. The military didn’t evacuate anyone. They slaughtered the uninfected on cattle cars and buses and they intend to nuke the town. They are afraid and aren’t going to take any chances.
As a result of the second turn the last quarter of the film gets a little out of control. Most of the movie, however, is restrained yet suspenseful.