In "Body of Evidence," movie audiences are asked to believe that a woman played by Madonna uses sex to murder a string of lovers who have weak hearts.
In "Sommersby," audiences are asked to believe that a wife played by Jodie Foster doesn't recognize her husband (Richard Gere) six years after he goes off to the Civil War--not even when they make love.
In "M. Butterfly," based on a true story, audiences are asked to believe that a male French diplomat had a multi-year sexual relationship with a man, who he thought was a woman. The film is due later this year starring Jeremy Irons and John Lone.
From "Prelude to a Kiss," where Meg Ryan plays a woman who wills her spirit into the body of an old man with terminal cancer at her wedding reception, to "Indecent Proposal," where Robert Redford plays a billionaire who offers a young couple $1 million if he can have sex with the wife, movie audiences are often asked to make giant leaps to accept a story's premise.
When it works well, as in "Big," a 1988 film in which a boy gets his wish from an amusement park fortune-telling machine to inhabit his own grown-up body, the result can be endearing.
When it doesn't, as in the 1987 movie "Like Father, Like Son," in which a dad and his son (Dudley Moore and Kirk Cameron) accidentally switch brains, the result can be easily forgettable.
But even though Hollywood studios lavish untold millions on actors, directors and sets, the question of whether a movie works or doesn't work can often come down to one intangible: whether the audience willingly suspends its disbelief.
"All art is contrivance," said Nicholas Meyer, who wrote "Sommersby," a screenplay with roots in a true account in 16th-Century France. "The trick is to conceal or to make palatable or innocuous the contrivance."
Some critics had trouble swallowing one of "Sommersby's" key premises--that Foster's character can sleep with a man who says he's her husband and not know if he's lying.
"I think that is a tough one to follow," said Newsday reviewer Jack Mathews. "Everybody has had intimate relationships with somebody. It's pretty hard to believe that even after six years have passed you wouldn't know that person in bed. You just know people's bodies too well, their height, the curvature of their face. I think any rational person would say, 'That is not possible.' Yet, 'Sommersby' is based on a true story."
Meyer said that although he enjoyed the finished film, he was troubled that the middle-aged Gere was selected for the role.
"As an actor, (Gere) did a superb job," Meyer said, "but my envisioning of it when I wrote it had the guy leaving home at age 20 and coming back at 26, having been a prisoner in a POW camp. . . . It would have been more plausible."
"As far back as 'King Kong' and 'The Cabinet of Dr. Caligari,' audiences have been asked to buy incredible premises in all kinds of (films)," said Robert McKee, a noted lecturer on screenwriting.
Problems develop, McKee said, when the writer sets up a world and then violates the internal reality of that world or handles things in an inconsistent way.
In the 1985 thriller "Jagged Edge," the plot revolved around an attorney (Glenn Close) who falls in love with her client, a publishing magnate (Jeff Bridges) accused of murdering his wife.
At the end of the movie, McKee points out, Close discovers an upright typewriter in her lover's closet that the man had used in plotting the wife's murder.
"We have to believe that this man who is absolutely so brilliant in the execution of his crime would actually leave the . . . typewriter he used to write notes in the closet of his house?" McKee asked. ". . . that's just bad writing."
Still, McKee noted, the film was a hit at the box office; he suspects audiences went along with the ending because they loved everything about the mystery leading up to it.
Amy Holden Jones, who wrote the screenplay adaptation of "Indecent Proposal," said some critics have not bought the premise of that film, but argues that the premise--a down-on-their-luck couple offered $1 million by a handsome billionaire for one night with the wife--is not implausible:
"I don't find the movie unrealistic at all," Jones said. "The audience buys the premise. It's the critics who don't buy the premise."
Fantastic premises have been the backbone of movies since the dawn of film, she said.
In the 1983 movie "Flashdance," for instance, audiences are asked to believe that gorgeous Jennifer Beals works as a welder while trying to become a big-time dancer.
"That film was destroyed by critics," Jones said, "but would anyone go to the movie if it wasn't Beals (playing the steelworker)? I don't want to see a fat old broad in a helmet."
Making a story believable is a crucial task of the screenwriter, said Phil Alden Robinson, who wrote the screenplay adaptation and directed the 1989 baseball fantasy "Field of Dreams."