Mack, a white man in a luxury car, is lost in a rough are, and threatened by black men. He (Kline) thinks he'll be killed until a tow truck driver - another black man - Simon (Glover) arrives and defuses the situation. But this film is not about fear. Dialogue throughout reflects how we really think and talk. "Do you respect me or my gun?" the gang leader asks. Glover says, "If you didn't have that gun, there's no way we'd have this conversation." After the incident, Kline buys Glover a cup of coffee, to thank the man he says saved him. The characters wouldn't ordinarily meet: Kline is a wealthy entertainment accountant, Glover a divorced, hardworking tow-truck driver. Removing social barriers is "Grand Canyon's" theme. In an ominous, alienating Los Angeles, rich people's money and distance protect them from poverty and despair. But Mack believes he's been granted new life, and wants to live differently. As with characters in two other Kasdan movies, "The Big Chill," and "The Accidental Tourist," he finds the proximity of death inspires him to live thoughtfully. Mack's wife (McDonnell) feels the same. Their house will soon be empty when their son goes college, but crying in the bushes along a daily jogging path is an abandoned baby. Mack's wife takes it home. The film's scene with the greatest sense of impending danger is during a driving lesson. Mack takes his son to practice left turns; there's a frightening undercurrent. Mack explains that you only have a split second to act before you get creamed.
Simon is worried about his nephew, who might be in a gang. Mack knows the owner of a building in a better area, but its dangers include police who think a young black man jogging is automatically suspicious. Mack sets up a date for Simon with a woman who works for him (Woodard); the couple realize Mack hardly knows them, and that they might be the only blacks he knows. As regard grows between Simon and Mack, Mack's wife falls in love with the baby. Another character in "Grand Canyon" is a producer of violent action pictures (Martin), who's angry when an editor cuts the "money shot" (a bus driver getting his brains shot out). When a mugger shoots Martin's leg, he vows not to make violent movies again. With our cities wounded, movies like "Grand Canyon" can help them.