It's summer in Sweet Valley, and the Wakefield twins and their friends are taking a bike trip up the beautiful California coast. What could be more exciting than four weeks of glorious sunshine, sandy beaches, and endless fun at every stop?
But the dream of a perfect vacation soon fades. Elizabeth Wakefield is about to break up with her boyfriend, Todd, over another girl. Her twin, Jessica, chases after sexy Robbie October, who ignores her. Bruce Patman is mean to his cousin Roger, Lila Fowler holds a grudge against Ms. Dalton, and Ms. Dalton is barely speaking to Mr. Collins. Can this fueding group unite when an unexpected disaastor threatens their lives?

"Now you're going to be absolutely terrific to everyone on this vacation, right?" Elizabeth was stern.
"OK, big sister, OK. Whatever you say." Jessica rolled her blue-green eyes skyward.
Elizabeth folded her arms across her chest. "Say it like you mean it, Jessica."
"Liz, I promise, I really do, that I'll be nice to everyone on this trip. I'm going to be so nice that they're going to give me the bike tripper of the year award." Jessica giggled.
"Jess, if that's true, I wouldn't miss this trip for anything in the world!" A brilliant smile lit up Elizabeth's face.
Jessica matched her twins smile - two identical rays of sunshine. "Count on it, Liz. This is going to be the best vacation we've ever had!"