As they prepare to make the traditional Christmas cookies known as bizcochitos, Christina's grandmother tells her the story of how a magical butterfly first introduced these sweet treats to her great-grandfather, a shepherd in the hills of New Mexico.

Nancy tries to solve the mystery of who is ruining campaign posters for Nancy's class election.

Who let the air out of the soccer ball? Who added salt to the water on the sidelines? Who put the red glop in the goalie's soccer shoes? Nancy Drew wants to know who's playing the silly games with her third grade soccer team.

Mari Cheng is a new girl in Nancy's class who has her unicorn stolen and Nancy is a special friend who is going to help her.

Nancy's housekeeper Hannah has a secret and Nancy is sure it is that Hannah has found another job. Nancy will do anything to keep Hannah, even clean the house.

Nancy and her friends open a lemonade stand in the park, but they find themselves out of business and on the trail of a mystery when their box of lemons is stolen.

Nancy and her friends have free passes for the local amusement park, but after their first day there, the passes disappear. Now Nancy needs to figure out who took the passes or else the girls will miss out on all the fun.

After seeing an article in a tabloid newspaper, Nancy and her friends wonder if their substitute teacher Ms. Zagon is the queen of the planet Zagon.

When Rebecca's slumber party invitations disappear, Nancy promises to try to find out who took them and why.