“Trapped” is a sour and unpleasant movie, a 90-minute ordeal that seems, in its small way, as torturous as the ordeal suffered by its characters.

For most of the film, not a single character is happy or even content. The film starts with a kidnapping and exists in perpetual climax from then on. It’s uncomfortable to watch. Charlize Theron and Stuart Townsend play Karen and Will Jennings, a happy, wealthy Oregon couple with an adorable little daughter, Abby (Dakota Fanning). Will is a successful doctor with a new miracle drug in development, while Karen’s a designer and a fabulous mom.

They are the targets of a trio of white-trashy kidnappers who have mapped out the perfect crime. Large, slow Marvin (Pruitt Taylor Vince) takes the girl to a remote location while oily mastermind Joe (Kevin Bacon) stays with Mom and sleazy femme fatale Cheryl (Courtney Love) corners Dad. It’s a divide-and-conquer plan, you see, and the beauty part is that the parents have no choice but to give up the ransom money. If anyone calls the police, Joe calls Marvin and tells him to kill the kid. If Joe or Cheryl doesn’t check in at the appointed times, Marvin is under instructions to kill the kid. If, after the ransom is paid and the family is reunited, anyone ever tells the police, Joe comes back and kills the kid. See? It’s so smart you’re probably already thinking of trying it.

But Karen won’t sit back and be the standard victim, and Will has some tricks up his sleeve, too, and it all goes horribly awry, as you might imagine (and, in fact, as you could probably write yourself). Written by Greg Iles (adapting his novel, “24 Hours”) and directed by Luis Mandoki (“Message in a Bottle,” “Angel Eyes”), the film is a standard women-in-peril potboiler: Cheryl has been abused by Joe, Joe harasses Karen, poor little Abby is terrified; why would this appeal to anyone?

The performances are good enough, but irrelevant, and Mandoki’s shaky camera work is more irritating than tension-building. I’m not sure how Will has ready access to the vice president of a cellphone company, but hooray that he does. The film has a finale that is more exciting than it ought to be, but trust me, you don’t want to endure everything else just for that.

D+ (1 hr., 30 min.; R, some harsh profanity, some strong sexuality, some strong violence.)