It's senior night at the local amusement park for students from McKinley High and the main attraction for most is the huge Devil's Flight roller coaster. That is, except for Wendy Christensen (MARY ELIZABETH WINSTEAD) who's there with her best friend Carrie (GINA HOLDEN) and their respective boyfriends Jason (JESSE MOSS) and Kevin Fischer (RYAN MERRIMAN). Wendy, who's taking photos for the school yearbook, is already nervous and refuses to sit in the front with Jason, thus ending up in the back with Kevin. But when she has a vision of a horrible and deadly derailment, she freaks out, thus causing a number of students to get off the train.
Jason and Carrie aren't among them and despite Wendy's efforts to stop the train, she's removed from the platform, only then to see her vision come true. As a result, those left on the train are all killed. Feeling overwhelming grief and guilt, Wendy just wants to graduate and be done with everything related to what occurred, but Kevin feels the need to take care of her since he promised that to Jason before the fateful ride.
Kevin also brings up previous events where the last-minute survivors of other deadly accidents ended up being killed one-by-one in the order they should have originally died. With clues apparently in the photos Wendy took that night at the amusement park, she and Kevin try to figure out who might be next and how they'll be killed.
Among those who got off the coaster before it crashed is the lascivious Frankie (SAM EASTON) who's obviously attracted to the elitist beauties Ashley (CHELAN SIMMONS) and Ashlyn (CRYSTAL LOWE). Jock Lewis (TEXAS BATTLE) thinks Wendy and Kevin are crazy and subsequently taunts Death to take him, while Goth student Ian (KRIS LEMCHE) and his girlfriend Erin (ALEXZ JOHNSON) are similarly skeptical, which also holds true for Wendy's younger sister Julie (AMANDA CREW) who had crashed the seniors only event. When the deaths start occurring, Wendy and Kevin do what they can to warn the others, all while taking steps they hope will protect themselves.