In "The Box," which is fairly insane by the standards of most Hollywood packages, writer-director Richard Kelly takes the 10-page story "Button, Button" by Richard Matheson (who wrote "I Am Legend" and many other works adapted for the screen) and stuffs it so full of cockamamie speculative fictions, from magical lightning strikes to NASA projects to the metaphorical uses of Sartre's "No Exit," by the end you can only think: This guy needed a bigger box.

The ethics test at the story's center adheres to Matheson's original. A man arrives one day at an upper-middle-class suburban couple's home, having previously placed a mysterious whatzit in plain brown wrapping paper at the couple's doorstep. The man tells the woman: Push the button on this thing, and you'll get rich. The hitch: Someone in the world will die as a result, someone you do not know.

Frank Langella plays the man with the box with the button and the secrets. He is just right -- a little menacing, a little comforting, a little earthly, a little not. (Digitally he has been given a grotesque facial disfiguring, which relates to the character's peculiar circumstances.) Everything else about "The Box" is not quite right, or not in the least right. Kelly's imagination is prodigious: The director's cut of his feature "Donnie Darko," which dealt with alternate realities and psychic visions in suburbia, is the place to start to find out if he's your kind of fantasist. Even crazier and messier, "Southland Tales" has its ardent admirers.

But Kelly is not yet his own best director. His scripts run in many directions at once, and he favors the dense back-story fabulations of the graphic-novel form. Behind the camera, though, he's a slowpoke and a bit of a visual drudge. Set in 1976, his free-form adaptation of Matheson's story trips the light fantastic but getting there isn't much fun.

Cameron Diaz is Norma, a literature professor with a bad foot and a handy allegorical interest in Sartre's "No Exit," which Kelly exploits like mad. Like Diaz, James Marsden (as a NASA engineer who worked on the Viking space probe) is not an actor given to playing two or three notes of panic, greed, doubt, whatever, at once. Their characters are soon in over their heads, but the actors seem that way, too -- petulant when they should be wrestling with bigger, more interesting clashes of emotion.

Cast in soft, ironically nostalgic light, a typical shot in "The Box" places Diaz and Marsden, or Diaz and Langella, at the family dining room table in stiff, precise profile, talking. The pacing throughout is languid. Your eye becomes fixated on the hideous '70s wallpaper behind them. If only the story's interstellar narrative developments had the intensity of that wallpaper. Rod Serling might've gotten a great hour out of it (the story, that is, not the wallpaper). It simply is not two hours' worth, no matter how many quantum leaps into the unknown Kelly takes.