Lewis Thomas (PAUL WALKER) is a college student who's going to drive across the country, picking up his hometown friend, Venna (LEELEE SOBIESKI), along the way. He makes a small detour beforehand, however, to bail his estranged brother, Fuller (STEVE ZAHN), out of jail.
As the two become reacquainted, Fuller persuades Lewis to pull a prank on an anonymous trucker they overhear on the CB radio. Acting like a woman named Candy Cane, Lewis tells the trucker - known only by his handle, "Rusty Nail" -- to meet "her" at a motel that night, giving the truck driver the number of the room next to theirs. Believing they're in for some fun, the brothers eavesdrop on the trucker's arrival next-door that night, but are horrified when they discover the next morning that he severely beat up the occupant of that room.
Back on the road, the two hear Rusty Nail on the CB again and learn to their horror that he knows who they are and is apparently following them. After a close call with the vindictive trucker where they apologize, the two pick up Venna and believe their troubles are behind them. Little do they know, however, that the trucker has more in store for them. From that point on, they and Venna do what they must to avoid the deranged truck driver.