Kelly's obsession with her weight leads to an addiction to diet pills that puts her health in imminent danger. Her friends plan a surprise party for her 18th birthday but the pills make her so paranoid that she thinks everyone is against her. Meanwhile, Brandon and Steve compete on a televised dating show for a date with the lovely Celeste Lundy.

It's Senior Ditch Day and the girls along with David, decide to spend it at Magic Mountain. What is supposed to be a fun day turns into a nightmare when Kelly's wallet is stolen and Donna is mugged. Meanwhile, Brandon encounters problems of his own when he has to cover for Nat by working at the Peach Pit, and his car is stolen by a clever female con artist who dupes both Dylan and Steve into tagging along with her to help search for Burt Reynolds to appease a tour group.