The Wakefield twins and their friends at Sweet Valley High are in festive spirits. It's Christmas vacation, the annual parade is just days away, secret Santas are busy buying surprise gifts, and everyone's talking about the holiday dance at the Patmans' mansion. Jessica Wakefield is determined to be named Miss Christmastime, and Elizabeth is counting the days until she's reunited with her faraway boyfriend, Todd Wilkins.

It seems nothing can spoil Jessica and Elizabeth's holiday-until Mr. and Mrs. Wakefield announce the arrival of an unwelcome houseguest. Now it looks as though this Christmas might be the worst ever!