The two stupidest words in the history of horror movies?

"Wait here!"

Fortunately, there aren't a lot of "Wait here" moments in "The Crazies," a lean little thriller that doesn't mess around.

Adapted from George A. Romero's 1973 zombie movie without zombies, this new "Crazies" brings horror home to the heartland as a small Iowa town copes with an outbreak of homicidal maniacs and the shoot-first military sent there to contain the contagion.

Timothy Olyphant ("Live Free or Die Hard," "Hitman") is Sheriff David Dutton, who keeps the peace in peaceful Ogden Marsh, Iowa.

He's the sort of caring lawman you'd hope for in a quiet town. When he has to shoot a deranged "town drunk" who staggers onto the baseball field in the middle of the game, brandishing a shotgun, Dutton suffers genuine remorse.

Radha Mitchell ("Silent Hill") is Dr. Judy Dutton, his wife. She treats a catatonic man in her clinic only to have him wipe out his family when he goes home.

"You know what? We're in trouble!"

Something has triggered this mania. Not everybody's sick, but that's the way the fellows in the black SUVs and black helicopters, and the soldiers in bio-chemical warfare suits treat them. Not only do the Duttons have to worry about which neighbors are murderous monsters and which worth saving, they must dodge trigger-happy troopers who are rounding up anyone they don't shoot on sight.

Director Breck Eisner ("Sahara") keeps the focus on the husband and wife, with a deputy and nurse (Joe Anderson, Danielle Panabaker) brought along for moral (and firepower) support. Chilling set pieces in a car wash and in the high school that's been turned into a triage center pay off with genuine chills. Eisner discovered the spine-tingle of knives and pitchforks dragged along concrete, of a whirring bone-saw clattering across a tile floor. Unlike many horror directors, he tries to put value on the lives that are lost, though he brings nothing else new to this paranoid genre.

The washed-out, "Book of Eli" colorations and stark locations (flat, brown cornfields) heighten the sense of isolation.

But after "Zombieland," "The Crazies" struggles to find novelty and laughs, and must battle the overwhelming sense that we've been here, seen this too often and too recently to experience any real surprises.